What is the Tree Depth-First Search (DFS) pattern in coding interviews?

Recursive top-down and bottom-up traversals on hierarchical structures It is categorized under Trees & Graphs and features 353 curated interview problems across Easy (42), Medium (224), and Hard (87) difficulties.

Which tech companies frequently test Tree Depth-First Search (DFS)?

Companies frequently asking Tree Depth-First Search (DFS) questions include Google, Amazon, Meta, Microsoft, Bloomberg, NeetCode 150.

How do I master the Tree Depth-First Search (DFS) pattern?

Start by studying the algorithmic strategy and template code, then practice Easy and Medium problems before attempting Hard problems under timed conditions.

Tree Depth-First Search (DFS)

Trees & Graphs

Recursive top-down and bottom-up traversals on hierarchical structures

353 problems·42 Easy·224 Medium·87 Hard

Pattern Study Guide & Cheat Sheet· O(N) visits each node once · O(H) call stack where H is tree height (O(log N) balanced, O(N) worst-case skewed)

▼

Traverse binary or general trees by recurring deep along branches, computing subtree metrics bottom-up (postorder) or passing state top-down (preorder).

Core Invariant: Recursive Trust: Assume `dfs(node.left)` and `dfs(node.right)` return the correct subtree answers. Combine them at `node` with the base case (`if not node: return base_val`).

Recognize it (Keywords & Signals)

Maximum / minimum depth of binary tree
Invert / clone binary tree
Diameter of binary tree
Lowest common ancestor (LCA)
Path sum / maximum path sum across branches
Check balanced binary tree

When NOT to use

Level-by-level processing or shortest path in terms of edge counts (Tree BFS is cleaner).

How to solve (Step-by-step)

1.Handle base case: `if not node: return 0` (or `None`, `True`).
2.Recursively solve left subtree: `left = dfs(node.left)`.
3.Recursively solve right subtree: `right = dfs(node.right)`.
4.Combine results at parent: e.g., update global variable `self.max_diameter = max(self.max_diameter, left + right)`.
5.Return single-branch contribution upward: `return 1 + max(left, right)`.

Watch for (Interview Traps)

Mixing up what is returned upward vs what updates the global answer (e.g. returning both branches to parent)
Recursion limit exceeded on deeply skewed trees (Python default limit is 1000)
Forgetting to handle `node is None` as base case

Bottom-Up Postorder Tree DFS (Diameter / Path Metric)

class TreeNode:
    def __init__(self, val=0, left=None, right=None):
        self.val = val
        self.left = left
        self.right = right

def diameter_of_binary_tree(root: TreeNode | None) -> int:
    max_diameter = 0
    
    def dfs(node: TreeNode | None) -> int:
        nonlocal max_diameter
        if not node:
            return 0  # Height of empty subtree
            
        # Postorder: solve children first
        left_height = dfs(node.left)
        right_height = dfs(node.right)
        
        # Invariant: longest path through current node spans both subtrees
        max_diameter = max(max_diameter, left_height + right_height)
        
        # Return single branch height upward to parent
        return 1 + max(left_height, right_height)
        
    dfs(root)
    return max_diameter

Cost: O(N) visits each node once · O(H) call stack where H is tree height (O(log N) balanced, O(N) worst-case skewed) (Avoids O(N^2) parent traversals.)

Canonical problems

#104 Maximum Depth of Binary Tree: 1 + max(dfs(left), dfs(right))

#226 Invert Binary Tree: Swap node.left and node.right recursively

#543 Diameter of Binary Tree: Combine left and right depths at each node

#236 Lowest Common Ancestor of a Binary Tree: Return node if target found in both subtrees

⌘K

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#314Binary Tree Vertical Order Traversal

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#96Unique Binary Search Trees

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#226Invert Binary Tree

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NeetCode 150NeetCode 150Josh Technology+6

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#173Binary Search Tree Iterator

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Josh TechnologyMongoDBLinkedIn+5

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#515Find Largest Value in Each Tree Row

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Josh TechnologyLinkedInApple+5

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#2196Create Binary Tree From Descriptions

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#310Minimum Height Trees

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#111Minimum Depth of Binary Tree

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#430Flatten a Multilevel Doubly Linked List

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#129Sum Root to Leaf Numbers

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#851Loud and Rich

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#765Couples Holding Hands

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#701Insert into a Binary Search Tree

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AndurilMicrosoftAmazon+4

#106Construct Binary Tree from Inorder and Postorder Traversal

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Walmart LabsMicrosoftTikTok+4

#94Binary Tree Inorder Traversal

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AndurilMicrosoftBloomberg+4

#802Find Eventual Safe States

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#117Populating Next Right Pointers in Each Node II

Medium·7 companies·Max freq 50%·Acc 57.8%

BloombergMetaMicrosoft+4

#428Serialize and Deserialize N-ary Tree

Hard·7 companies·Max freq 39%·Acc 68.9%

AppleNvidiaTikTok+4

#1245Tree Diameter

Medium·7 companies·Max freq 39%·Acc 61.3%

TikTokSalesforceMeta+4

#1559Detect Cycles in 2D Grid

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#285Inorder Successor in BST

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thoughtspotWeRideUber+3

#339Nested List Weight Sum

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#2096Step-By-Step Directions From a Binary Tree Node to Another

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#1022Sum of Root To Leaf Binary Numbers

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LimeAmazonBloomberg+3

#2467Most Profitable Path in a Tree

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#938Range Sum of BST

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MetaYandexGoogle+3

#366Find Leaves of Binary Tree

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#690Employee Importance

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RobinhoodUberGoogle+3

#404Sum of Left Leaves

Easy·6 companies·Max freq 75%·Acc 62.9%

GrammarlyMetaMicrosoft+3

#1028Recover a Tree From Preorder Traversal

Hard·6 companies·Max freq 70%·Acc 83.3%

GrammarlyAmazonGoogle+3

#2493Divide Nodes Into the Maximum Number of Groups

Hard·6 companies·Max freq 63%·Acc 66.9%

UberAccentureGoogle+3

#386Lexicographical Numbers

Medium·6 companies·Max freq 53%·Acc 76.3%

BarclaysBloombergGoogle+3

#993Cousins in Binary Tree

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AdobeBloombergAmazon+3

#872Leaf-Similar Trees

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SnowflakeMetaAmazon+3

#1462Course Schedule IV

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TikTokUberAmazon+3

#1008Construct Binary Search Tree from Preorder Traversal

Medium·6 companies·Max freq 38%·Acc 84.4%

AmazonSalesforceMeta+3

#1020Number of Enclaves

Medium·6 companies·Max freq 27%·Acc 72.0%

GoogleBloombergMicrosoft+3

#700Search in a Binary Search Tree

Easy·6 companies·Max freq 25%·Acc 82.9%

GoogleMetaAmazon+3

#107Binary Tree Level Order Traversal II

Medium·6 companies·Max freq 25%·Acc 68.6%

OracleBloombergAmazon+3

#889Construct Binary Tree from Preorder and Postorder Traversal

Medium·6 companies·Max freq 25%·Acc 78.1%

AppleGoogleBloomberg+3

#1267Count Servers that Communicate

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OracleAmazonMicrosoft+3

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Medium·5 companies·Max freq 100%·Acc 72.5%

HuluMetaMicrosoft+2

#655Print Binary Tree

Medium·5 companies·Max freq 100%·Acc 66.7%

PoyntGoogleMeta+2

#255Verify Preorder Sequence in Binary Search Tree

Medium·5 companies·Max freq 100%·Acc 51.8%

ZenefitsExpediaSalesforce+2

#958Check Completeness of a Binary Tree

Medium·5 companies·Max freq 75%·Acc 59.3%

LyftMetaMicrosoft+2

#1026Maximum Difference Between Node and Ancestor

Medium·5 companies·Max freq 63%·Acc 78.2%

Josh TechnologyEPAM SystemsAmazon+2

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Medium·5 companies·Max freq 63%·Acc 63.8%

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#797All Paths From Source to Target

Medium·5 companies·Max freq 63%·Acc 83.7%

BloombergNetflixAmazon+2

#2316Count Unreachable Pairs of Nodes in an Undirected Graph

Medium·5 companies·Max freq 63%·Acc 0.5%

SnapSnapAmazon+2

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Hard·5 companies·Max freq 60%·Acc 61.8%

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CitadelMetaAmazon+2

#505The Maze II

Medium·5 companies·Max freq 54%·Acc 55.2%

UberTikTokGoogle+2

#1466Reorder Routes to Make All Paths Lead to the City Zero

Medium·5 companies·Max freq 50%·Acc 66.0%

TikTokMicrosoftAmazon+2

#2583Kth Largest Sum in a Binary Tree

Medium·5 companies·Max freq 39%·Acc 59.0%

VisaAmazonBloomberg+2

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Hard·5 companies·Max freq 38%·Acc 56.4%

DoorDashAppleGoogle+2

#1382Balance a Binary Search Tree

Medium·5 companies·Max freq 38%·Acc 86.3%

AmazonMetaMicrosoft+2

#1971Find if Path Exists in Graph

Easy·5 companies·Max freq 38%·Acc 55.5%

BloombergMicrosoftAmazon+2

#1254Number of Closed Islands

Medium·5 companies·Max freq 38%·Acc 67.2%

OracleGoogleMicrosoft+2

#1373Maximum Sum BST in Binary Tree

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AmazonGoogleMicrosoft+2

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#894All Possible Full Binary Trees

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NvidiaSalesforceGoogle+2

#95Unique Binary Search Trees II

Medium·5 companies·Max freq 28%·Acc 62.8%

MetaAmazonGoogle+2

#144Binary Tree Preorder Traversal

Easy·5 companies·Max freq 27%·Acc 76.2%

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#145Binary Tree Postorder Traversal

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AmazonBloombergGoogle+2

#2236Root Equals Sum of Children

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#965Univalued Binary Tree

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#3068Find the Maximum Sum of Node Values

Hard·4 companies·Max freq 100%·Acc 69.4%

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WixGoogleMeta+1

#1034Coloring A Border

Medium·4 companies·Max freq 88%·Acc 0.5%

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#250Count Univalue Subtrees

Medium·4 companies·Max freq 88%·Acc 57.5%

6senseZeta GlobalAmazon+1

#2359Find Closest Node to Given Two Nodes

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Sumo LogicSumo LogicGoogle+1

#385Mini Parser

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AirbnbMetaAmazon+1

#449Serialize and Deserialize BST

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ShopeeAmazonMicrosoft+1

#1325Delete Leaves With a Given Value

Medium·4 companies·Max freq 67%·Acc 77.2%

Josh TechnologyAmazonMicrosoft+1

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MetaTikTokAmazon+1

#1315Sum of Nodes with Even-Valued Grandparent

Medium·4 companies·Max freq 63%·Acc 86.0%

Josh TechnologySalesforceAmazon+1

#1110Delete Nodes And Return Forest

Medium·4 companies·Max freq 63%·Acc 72.5%

PinterestGoogleMeta+1

#2192All Ancestors of a Node in a Directed Acyclic Graph

Medium·4 companies·Max freq 63%·Acc 62.3%

OracleGoogleAmazon+1

#1676Lowest Common Ancestor of a Binary Tree IV

Medium·4 companies·Max freq 63%·Acc 79.6%

AtlassianAmazonTikTok+1

#2265Count Nodes Equal to Average of Subtree

Medium·4 companies·Max freq 53%·Acc 86.8%

MetaSnowflakeAmazon+1

#1644Lowest Common Ancestor of a Binary Tree II

Medium·4 companies·Max freq 51%·Acc 69.7%

LinkedInMetaAtlassian+1

#737Sentence Similarity II

Medium·4 companies·Max freq 50%·Acc 51.4%

RipplingAppleGoogle+1

#298Binary Tree Longest Consecutive Sequence

Medium·4 companies·Max freq 50%·Acc 54.8%

TikTokGoogleMeta+1

#669Trim a Binary Search Tree

Medium·4 companies·Max freq 42%·Acc 66.8%

AdobeBloombergAmazon+1

#1970Last Day Where You Can Still Cross

Hard·4 companies·Max freq 41%·Acc 68.7%

AtlassianGoogleMeta+1

#582Kill Process

Medium·4 companies·Max freq 39%·Acc 70.7%

OracleBloombergAmazon+1

#865Smallest Subtree with all the Deepest Nodes

Medium·4 companies·Max freq 39%·Acc 77.6%

MetaBloombergAmazon+1

#1123Lowest Common Ancestor of Deepest Leaves

Medium·4 companies·Max freq 38%·Acc 79.5%

MetaGoogleBloomberg+1

#2872Maximum Number of K-Divisible Components

Hard·4 companies·Max freq 38%·Acc 74.0%

InfosysGoogleAmazon+1

#1161Maximum Level Sum of a Binary Tree

Medium·4 companies·Max freq 28%·Acc 70.0%

GoogleMetaMicrosoft+1

#654Maximum Binary Tree

Medium·4 companies·Max freq 27%·Acc 86.4%

MicrosoftMetaGoogle+1

#1483Kth Ancestor of a Tree Node

Hard·4 companies·Max freq 27%·Acc 38.9%

GoogleGoldman SachsAmazon+1

#388Longest Absolute File Path

Medium·4 companies·Max freq 26%·Acc 49.6%

GoogleMetaAmazon+1

#501Find Mode in Binary Search Tree

Easy·4 companies·Max freq 25%·Acc 59.1%

GoogleMetaAmazon+1

#637Average of Levels in Binary Tree

Easy·4 companies·Max freq 25%·Acc 75.0%

MetaAmazonMicrosoft+1

#538Convert BST to Greater Tree

Medium·4 companies·Max freq 25%·Acc 71.8%

AmazonMicrosoftMeta+1

#2322Minimum Score After Removals on a Tree

Hard·4 companies·Max freq 25%·Acc 76.1%

AmazonMetaMicrosoft+1

#1289Minimum Falling Path Sum II

Hard·4 companies·Max freq 25%·Acc 63.0%

GoogleMetaBloomberg+1

#2685Count the Number of Complete Components

Medium·4 companies·Max freq 16%·Acc 80.8%

MicrosoftMetaAmazon+1

#2658Maximum Number of Fish in a Grid

Medium·4 companies·Max freq 13%·Acc 70.3%

MetaAmazonMicrosoft+1

#364Nested List Weight Sum II

Medium·3 companies·Max freq 100%·Acc 67.0%

LinkedInMetaGoogle

#3367Maximize Sum of Weights after Edge Removals

Hard·3 companies·Max freq 100%·Acc 0.3%

GameskraftUberLinkedIn

#1391Check if There is a Valid Path in a Grid

Medium·3 companies·Max freq 100%·Acc 64.5%

RobinhoodSamsungGoogle

#563Binary Tree Tilt

Easy·3 companies·Max freq 100%·Acc 66.1%

IndeedMetaAmazon

#3067Count Pairs of Connectable Servers in a Weighted Tree Network

Medium·3 companies·Max freq 100%·Acc 56.2%

UBSthoughtspotRippling

#1993Operations on Tree

Medium·3 companies·Max freq 100%·Acc 45.7%

JuspayGoogleAmazon

#2471Minimum Number of Operations to Sort a Binary Tree by Level

Medium·3 companies·Max freq 100%·Acc 74.3%

GuidewireAmazonGoogle

#749Contain Virus

Hard·3 companies·Max freq 100%·Acc 55.1%

FlipkartBloombergGoogle

#623Add One Row to Tree

Medium·3 companies·Max freq 100%·Acc 64.2%

Gilt GroupeBloombergGoogle

#3715Sum of Perfect Square Ancestors

Hard·3 companies·Max freq 92%·Acc 42.8%

MeeshoAmazonGoogle

#510Inorder Successor in BST II

Medium·3 companies·Max freq 78%·Acc 61.1%

Arista NetworksMetaGoogle

#1302Deepest Leaves Sum

Medium·3 companies·Max freq 75%·Acc 86.6%

MyntraTikTokGoogle

#2049Count Nodes With the Highest Score

Medium·3 companies·Max freq 75%·Acc 52.9%

VisaDoorDashAmazon

#1102Path With Maximum Minimum Value

Medium·3 companies·Max freq 68%·Acc 54.7%

GeicoGoogleAmazon

#272Closest Binary Search Tree Value II

Hard·3 companies·Max freq 63%·Acc 61.2%

LinkedInGoogleAmazon

#671Second Minimum Node In a Binary Tree

Easy·3 companies·Max freq 63%·Acc 46.2%

LinkedInMetaAmazon

#742Closest Leaf in a Binary Tree

Medium·3 companies·Max freq 63%·Acc 47.5%

DatabricksLinkedInAmazon

#3387Maximize Amount After Two Days of Conversions

Medium·3 companies·Max freq 60%·Acc 61.7%

RipplingUberGoogle

#1038Binary Search Tree to Greater Sum Tree

Medium·3 companies·Max freq 56%·Acc 88.4%

SAPAmazonGoogle

#514Freedom Trail

Hard·3 companies·Max freq 54%·Acc 59.4%

PhonePeUberGoogle

#472Concatenated Words

Hard·3 companies·Max freq 53%·Acc 49.9%

AmazoneBayTikTok

#565Array Nesting

Medium·3 companies·Max freq 51%·Acc 56.7%

AppleAmazonGoogle

#536Construct Binary Tree from String

Medium·3 companies·Max freq 50%·Acc 58.7%

MetaAmazonBloomberg

#1530Number of Good Leaf Nodes Pairs

Medium·3 companies·Max freq 50%·Acc 71.8%

ByteDanceTikTokGoogle

#2097Valid Arrangement of Pairs

Hard·3 companies·Max freq 50%·Acc 66.6%

Goldman SachsAmazonGoogle

#1778Shortest Path in a Hidden Grid

Medium·3 companies·Max freq 40%·Acc 44.7%

MetaBloombergGoogle

#1522Diameter of N-Ary Tree

Medium·3 companies·Max freq 38%·Acc 75.5%

SalesforceMetaGoldman Sachs

#1609Even Odd Tree

Medium·3 companies·Max freq 38%·Acc 67.2%

BloombergMetaAmazon

#2458Height of Binary Tree After Subtree Removal Queries

Hard·3 companies·Max freq 38%·Acc 54.9%

SnowflakeGoogleMeta

#530Minimum Absolute Difference in BST

Easy·3 companies·Max freq 29%·Acc 59.5%

GoogleMetaAmazon

#508Most Frequent Subtree Sum

Medium·3 companies·Max freq 27%·Acc 69.4%

AmazonBloombergMicrosoft

#1361Validate Binary Tree Nodes

Medium·3 companies·Max freq 25%·Acc 44.2%

MetaMicrosoftGoogle

#2596Check Knight Tour Configuration

Medium·3 companies·Max freq 25%·Acc 61.7%

MetaAmazonGoogle

#606Construct String from Binary Tree

Medium·3 companies·Max freq 25%·Acc 70.8%

TikTokAmazonMeta

#1506Find Root of N-Ary Tree

Medium·3 companies·Max freq 25%·Acc 78.6%

BloombergGoogleMeta

#549Binary Tree Longest Consecutive Sequence II

Medium·3 companies·Max freq 25%·Acc 50.1%

UberGoogleMeta

#919Complete Binary Tree Inserter

Medium·3 companies·Max freq 25%·Acc 65.2%

GoogleMetaAmazon

#2421Number of Good Paths

Hard·3 companies·Max freq 25%·Acc 56.5%

GoogleAmazonBloomberg

#590N-ary Tree Postorder Traversal

Easy·3 companies·Max freq 13%·Acc 81.1%

BloombergAmazonGoogle

#3559Number of Ways to Assign Edge Weights II

Hard·3 companies·Max freq 13%·Acc 72.5%

BloombergAmazonGoogle

#3310Remove Methods From Project

Medium·3 companies·Max freq 13%·Acc 0.7%

BloombergAmazonGoogle

#429N-ary Tree Level Order Traversal

Medium·3 companies·Max freq 13%·Acc 71.6%

AmazonMicrosoftGoogle

#1932Merge BSTs to Create Single BST

Hard·3 companies·Max freq 13%·Acc 39.6%

AmazonMicrosoftGoogle

#1992Find All Groups of Farmland

Medium·2 companies·Max freq 100%·Acc 75.5%

CitrixGoogle

#3372Maximize the Number of Target Nodes After Connecting Trees I

Medium·2 companies·Max freq 100%·Acc 69.4%

JioGoogle

#3373Maximize the Number of Target Nodes After Connecting Trees II

Hard·2 companies·Max freq 100%·Acc 73.1%

JioGoogle

#2368Reachable Nodes With Restrictions

Medium·2 companies·Max freq 100%·Acc 60.6%

MakeMyTripGoogle

#776Split BST

Medium·2 companies·Max freq 100%·Acc 82.2%

CoupangAmazon

#3123Find Edges in Shortest Paths

Hard·2 companies·Max freq 100%·Acc 46.9%

WeRideDoorDash

#928Minimize Malware Spread II

Hard·2 companies·Max freq 100%·Acc 45.8%

DropboxUber

#1457Pseudo-Palindromic Paths in a Binary Tree

Medium·2 companies·Max freq 100%·Acc 68.4%

BCGAmazon

#3710Maximum Partition Factor

Hard·2 companies·Max freq 93%·Acc 32.1%

GameskraftGoogle

#1519Number of Nodes in the Sub-Tree With the Same Label

Medium·2 companies·Max freq 88%·Acc 55.5%

SamsungUber

#559Maximum Depth of N-ary Tree

Easy·2 companies·Max freq 88%·Acc 73.7%

DatadogAmazon

#1104Path In Zigzag Labelled Binary Tree

Medium·2 companies·Max freq 88%·Acc 75.8%

spinnyBloomberg

#2328Number of Increasing Paths in a Grid

Hard·2 companies·Max freq 88%·Acc 57.3%

AdobeMicrosoft

#1600Throne Inheritance

Medium·2 companies·Max freq 88%·Acc 67.4%

SnowflakeGoogle

#1377Frog Position After T Seconds

Hard·2 companies·Max freq 83%·Acc 38.7%

InMobiGoogle

#3619Count Islands With Total Value Divisible by K

Medium·2 companies·Max freq 79%·Acc 56.2%

IntuitGoogle

#156Binary Tree Upside Down

Medium·2 companies·Max freq 75%·Acc 65.5%

LinkedInGoogle

#3004Maximum Subtree of the Same Color

Medium·2 companies·Max freq 75%·Acc 58.8%

BlackRockMicrosoft

#1724Checking Existence of Edge Length Limited Paths II

Hard·2 companies·Max freq 75%·Acc 51.6%

Oscar HealthGoogle

#1042Flower Planting With No Adjacent

Medium·2 companies·Max freq 70%·Acc 53.9%

VimeoBloomberg

#2307Check for Contradictions in Equations

Hard·2 companies·Max freq 50%·Acc 44.0%

UberAmazon

#676Implement Magic Dictionary

Medium·2 companies·Max freq 45%·Acc 58.0%

BloombergGoogle

#2204Distance to a Cycle in Undirected Graph

Hard·2 companies·Max freq 38%·Acc 73.9%

OracleMicrosoft

#1820Maximum Number of Accepted Invitations

Medium·2 companies·Max freq 38%·Acc 52.7%

BloombergGoogle

#333Largest BST Subtree

Medium·2 companies·Max freq 27%·Acc 45.9%

MicrosoftMeta

#1810Minimum Path Cost in a Hidden Grid

Medium·2 companies·Max freq 27%·Acc 59.0%

MetaGoogle

#1485Clone Binary Tree With Random Pointer

Medium·2 companies·Max freq 27%·Acc 81.3%

AmazonMeta

#2641Cousins in Binary Tree II

Medium·2 companies·Max freq 27%·Acc 75.9%

AmazonGoogle

#711Number of Distinct Islands II

Hard·2 companies·Max freq 25%·Acc 55.5%

AmazonGoogle

#1740Find Distance in a Binary Tree

Medium·2 companies·Max freq 25%·Acc 74.4%

AppleAmazon

#1305All Elements in Two Binary Search Trees

Medium·2 companies·Max freq 25%·Acc 80.3%

AmazonMeta

#988Smallest String Starting From Leaf

Medium·2 companies·Max freq 25%·Acc 61.3%

GoogleAmazon

#1145Binary Tree Coloring Game

Medium·2 companies·Max freq 25%·Acc 53.0%

GoogleAmazon

#1261Find Elements in a Contaminated Binary Tree

Medium·2 companies·Max freq 25%·Acc 84.1%

GoogleAmazon

#3419Minimize the Maximum Edge Weight of Graph

Medium·2 companies·Max freq 25%·Acc 45.1%

UberGoogle

#3593Minimum Increments to Equalize Leaf Paths

Medium·2 companies·Max freq 16%·Acc 41.4%

GoogleMicrosoft

#3558Number of Ways to Assign Edge Weights I

Medium·2 companies·Max freq 13%·Acc 64.0%

MetaAmazon

#3562Maximum Profit from Trading Stocks with Discounts

Hard·2 companies·Max freq 13%·Acc 56.5%

MetaGoogle

#897Increasing Order Search Tree

Easy·2 companies·Max freq 13%·Acc 79.0%

AmazonGoogle

#589N-ary Tree Preorder Traversal

Easy·2 companies·Max freq 13%·Acc 76.9%

AmazonGoogle

#1372Longest ZigZag Path in a Binary Tree

Medium·2 companies·Max freq 13%·Acc 67.3%

AmazonMicrosoft

#3235Check if the Rectangle Corner Is Reachable

Hard·2 companies·Max freq 13%·Acc 25.2%

AmazonGoogle

#2876Count Visited Nodes in a Directed Graph

Hard·1 companies·Max freq 100%·Acc 31.1%

BNY Mellon

#2509Cycle Length Queries in a Tree

Hard·1 companies·Max freq 100%·Acc 60.6%

Arcesium

#2440Create Components With Same Value

Hard·1 companies·Max freq 100%·Acc 53.7%

Sprinklr

#666Path Sum IV

Medium·1 companies·Max freq 100%·Acc 62.9%

Alibaba

#2005Subtree Removal Game with Fibonacci Tree

Hard·1 companies·Max freq 100%·Acc 57.8%

Sony

#2846Minimum Edge Weight Equilibrium Queries in a Tree

Hard·1 companies·Max freq 90%·Acc 47.0%

Sprinklr

#2378Choose Edges to Maximize Score in a Tree

Medium·1 companies·Max freq 90%·Acc 56.8%

Sprinklr

#1257Smallest Common Region

Medium·1 companies·Max freq 88%·Acc 68.3%

Airbnb

#1916Count Ways to Build Rooms in an Ant Colony

Hard·1 companies·Max freq 88%·Acc 51.8%

Adobe

#3787Find Diameter Endpoints of a Tree

Medium·1 companies·Max freq 84%·Acc 66.9%

Agoda

#3820Pythagorean Distance Nodes in a Tree

Medium·1 companies·Max freq 78%·Acc 58.0%

PayPal

#2920Maximum Points After Collecting Coins From All Nodes

Hard·1 companies·Max freq 75%·Acc 36.9%

DE Shaw

#3383Minimum Runes to Add to Cast Spell

Hard·1 companies·Max freq 75%·Acc 44.7%

DE Shaw

#3575Maximum Good Subtree Score

Hard·1 companies·Max freq 75%·Acc 45.7%

Infosys

#2445Number of Nodes With Value One

Medium·1 companies·Max freq 75%·Acc 66.3%

Infosys

#2867Count Valid Paths in a Tree

Hard·1 companies·Max freq 64%·Acc 36.6%

Gameskraft

#3939Count Non Adjacent Subsets in a Rooted Tree

Hard·1 companies·Max freq 63%·Acc 56.1%

Infosys

#3515Shortest Path in a Weighted Tree

Hard·1 companies·Max freq 56%·Acc 42.6%

Juspay

#3313Find the Last Marked Nodes in Tree

Hard·1 companies·Max freq 55%·Acc 56.5%

Salesforce

#3528Unit Conversion I

Medium·1 companies·Max freq 52%·Acc 54.1%

Adobe

#1719Number Of Ways To Reconstruct A Tree

Hard·1 companies·Max freq 50%·Acc 46.2%

Uber

#3481Apply Substitutions

Medium·1 companies·Max freq 43%·Acc 77.9%

Google

#2673Make Costs of Paths Equal in a Binary Tree

Medium·1 companies·Max freq 39%·Acc 58.8%

TikTok

#672Bulb Switcher II

Medium·1 companies·Max freq 38%·Acc 50.4%

Microsoft

#3772Maximum Subgraph Score in a Tree

Hard·1 companies·Max freq 29%·Acc 71.0%

Microsoft

#1628Design an Expression Tree With Evaluate Function

Medium·1 companies·Max freq 28%·Acc 82.5%

Amazon

#1273Delete Tree Nodes

Medium·1 companies·Max freq 27%·Acc 61.6%

Microsoft

#1469Find All The Lonely Nodes

Easy·1 companies·Max freq 27%·Acc 84.1%

Microsoft

#3157Find the Level of Tree with Minimum Sum

Medium·1 companies·Max freq 27%·Acc 69.5%

Microsoft

#1379Find a Corresponding Node of a Binary Tree in a Clone of That Tree

Easy·1 companies·Max freq 27%·Acc 85.9%

Meta

#1586Binary Search Tree Iterator II

Medium·1 companies·Max freq 25%·Acc 63.5%

Meta

#998Maximum Binary Tree II

Medium·1 companies·Max freq 25%·Acc 70.7%

Meta

#1973Count Nodes Equal to Sum of Descendants

Medium·1 companies·Max freq 25%·Acc 77.3%

Meta

#3535Unit Conversion II

Medium·1 companies·Max freq 25%·Acc 65.8%

TikTok

#1214Two Sum BSTs

Medium·1 companies·Max freq 25%·Acc 68.2%

Amazon

#1080Insufficient Nodes in Root to Leaf Paths

Medium·1 companies·Max freq 25%·Acc 55.4%

Amazon

#2973Find Number of Coins to Place in Tree Nodes

Hard·1 companies·Max freq 25%·Acc 37.7%

Amazon

#3786Total Sum of Interaction Cost in Tree Groups

Hard·1 companies·Max freq 25%·Acc 54.4%

Amazon

#663Equal Tree Partition

Medium·1 companies·Max freq 25%·Acc 42.3%

Amazon

#1120Maximum Average Subtree

Medium·1 companies·Max freq 25%·Acc 67.0%

Amazon

#1490Clone N-ary Tree

Medium·1 companies·Max freq 25%·Acc 83.2%

Amazon

#1597Build Binary Expression Tree From Infix Expression

Hard·1 companies·Max freq 25%·Acc 62.9%

Amazon

#2123Minimum Operations to Remove Adjacent Ones in Matrix

Hard·1 companies·Max freq 25%·Acc 43.6%

Amazon

#753Cracking the Safe

Hard·1 companies·Max freq 25%·Acc 58.5%

Google

#3327Check if DFS Strings Are Palindromes

Hard·1 companies·Max freq 25%·Acc 20.8%

Google

#331Verify Preorder Serialization of a Binary Tree

Medium·1 companies·Max freq 25%·Acc 47.5%

Google

#2476Closest Nodes Queries in a Binary Search Tree

Medium·1 companies·Max freq 25%·Acc 44.7%

Google

#2556Disconnect Path in a Binary Matrix by at Most One Flip

Medium·1 companies·Max freq 25%·Acc 28.0%

Google

#302Smallest Rectangle Enclosing Black Pixels

Hard·1 companies·Max freq 25%·Acc 61.0%

Google

#2331Evaluate Boolean Binary Tree

Easy·1 companies·Max freq 25%·Acc 82.4%

Google

#685Redundant Connection II

Hard·1 companies·Max freq 25%·Acc 36.4%

Google

#1516Move Sub-Tree of N-Ary Tree

Hard·1 companies·Max freq 25%·Acc 59.8%

Google

#1602Find Nearest Right Node in Binary Tree

Medium·1 companies·Max freq 25%·Acc 75.1%

Google

#1612Check If Two Expression Trees are Equivalent

Medium·1 companies·Max freq 25%·Acc 71.8%

Google

#1660Correct a Binary Tree

Medium·1 companies·Max freq 25%·Acc 74.3%

Google

#1666Change the Root of a Binary Tree

Medium·1 companies·Max freq 25%·Acc 75.0%

Google

#1766Tree of Coprimes

Hard·1 companies·Max freq 25%·Acc 44.4%

Google

#1858Longest Word With All Prefixes

Medium·1 companies·Max freq 25%·Acc 72.1%

Google

#2313Minimum Flips in Binary Tree to Get Result

Hard·1 companies·Max freq 25%·Acc 57.0%

Google

#2689Extract Kth Character From The Rope Tree

Easy·1 companies·Max freq 25%·Acc 73.3%

Google

#2925Maximum Score After Applying Operations on a Tree

Medium·1 companies·Max freq 25%·Acc 47.5%

Google

#3493Properties Graph

Medium·1 companies·Max freq 13%·Acc 49.1%

Amazon

#3585Find Weighted Median Node in Tree

Hard·1 companies·Max freq 13%·Acc 26.2%

Google

#3319K-th Largest Perfect Subtree Size in Binary Tree

Medium·1 companies·Max freq 13%·Acc 62.4%

Google

#3486Longest Special Path II

Hard·1 companies·Max freq 13%·Acc 19.8%

Google

#2277Closest Node to Path in Tree

Hard·1 companies·Max freq 13%·Acc 62.5%

Google

#499The Maze III

Hard·1 companies·Max freq 13%·Acc 52.5%

Google

#	Problem	Difficulty	Top Companies↓	Frequency	Acceptance
#200	Number of Islands ArrayDepth-First SearchBreadth-First SearchUnion-FindMatrix	Medium	Hive Anduril Tinkoff Redfin+86	100%	64.7%
#207	Course Schedule Depth-First SearchBreadth-First SearchGraph TheoryTopological SortDirected Acyclic Graph	Medium	Zenefits Graviton Yelp Nordstrom+46	100%	51.8%
#210	Course Schedule II Depth-First SearchBreadth-First SearchGraph TheoryTopological Sort	Medium	Zenefits instabase Snowflake Netflix+35	100%	55.9%
#79	Word Search ArrayStringBacktrackingDepth-First SearchMatrix	Medium	Faire Karat NeetCode 150 Uber+35	100%	47.7%
#124	Binary Tree Maximum Path Sum Dynamic ProgrammingTreeDepth-First SearchBinary TreeDP on Trees	Hard	Baidu DoorDash Wix NeetCode 150+25	100%	42.5%
#332	Reconstruct Itinerary ArrayStringDepth-First SearchGraph TheorySortingHeap (Priority Queue)Eulerian CircuitEulerian PathSemi-Eulerian Graph	Hard	Hopper Pinterest Netflix Compass+22	100%	44.7%
#399	Evaluate Division ArrayStringDepth-First SearchBreadth-First SearchUnion-FindGraph TheoryShortest PathBellman–Ford AlgorithmFloyd–Warshall Algorithm	Medium	Tower Research Capital Tower Research Capital Urban Company DP world+21	100%	64.4%
#297	Serialize and Deserialize Binary Tree StringTreeDepth-First SearchBreadth-First SearchDesignBinary Tree	Hard	Yahoo Hive NeetCode 150 Quora+21	100%	61.1%
#236	Lowest Common Ancestor of a Binary Tree TreeDepth-First SearchBinary TreeBinary LiftingLowest Common Ancestor	Medium	NewsBreak Airwallex Meta Wix+20	100%	69.7%
#269	Alien Dictionary ArrayStringDepth-First SearchBreadth-First SearchGraph TheoryTopological SortDirected Acyclic Graph	Hard	X Pocket Gems Uber X+20	100%	37.3%
#543	Diameter of Binary Tree TreeDepth-First SearchBinary TreeDP on Trees	Easy	Meta Wix NeetCode 150 Nutanix+19	88%	65.8%
#98	Validate Binary Search Tree TreeDepth-First SearchBinary Search TreeBinary Tree	Medium	Wix NeetCode 150 Ola Cabs Millennium+19	88%	36.0%
#787	Cheapest Flights Within K Stops Dynamic ProgrammingDepth-First SearchBreadth-First SearchGraph TheoryHeap (Priority Queue)Shortest Path	Medium	HTC MakeMyTrip Stripe Airbnb+18	100%	42.2%
#695	Max Area of Island ArrayDepth-First SearchBreadth-First SearchUnion-FindMatrix	Medium	Schlumberger Grubhub Roku NeetCode 150+18	100%	74.1%
#341	Flatten Nested List Iterator StackTreeDepth-First SearchDesignQueueIterator	Medium	X HBO Mixpanel X+16	100%	65.8%
#104	Maximum Depth of Binary Tree TreeDepth-First SearchBreadth-First SearchBinary Tree	Easy	Yahoo NeetCode 150 Arista Networks Avito+16	100%	78.4%
#133	Clone Graph Hash TableDepth-First SearchBreadth-First SearchGraph Theory	Medium	Flexport Pocket Gems Wix NeetCode 150+16	100%	65.7%
#329	Longest Increasing Path in a Matrix ArrayDynamic ProgrammingDepth-First SearchBreadth-First SearchGraph TheoryTopological SortMemoizationMatrixDirected Acyclic Graph	Hard	DoorDash WeRide Duolingo Nutanix+16	93%	56.8%
#863	All Nodes Distance K in Binary Tree Hash TableTreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Okta Wix Zepto Meta+16	89%	67.8%
#103	Binary Tree Zigzag Level Order Traversal TreeBreadth-First SearchBinary Tree	Medium	Sigmoid Nutanix Adobe Walmart Labs+15	100%	64.1%
#102	Binary Tree Level Order Traversal TreeBreadth-First SearchBinary Tree	Medium	Gojek NeetCode 150 Palo Alto Networks Apple+14	100%	73.0%
#934	Shortest Bridge ArrayDepth-First SearchBreadth-First SearchMatrix	Medium	Tower Research Capital McKinsey Tower Research Capital Coupang+14	100%	59.6%
#968	Binary Tree Cameras Dynamic ProgrammingTreeDepth-First SearchBinary TreeDP on Trees	Hard	DE Shaw Graviton MathWorks DP world+13	100%	48.0%
#64	Minimum Path Sum ArrayDynamic ProgrammingMatrix	Medium	Texas Instruments SpaceX Goldman Sachs General Motors+13	100%	68.5%
#199	Binary Tree Right Side View TreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Meta Wix NeetCode 150 Oracle+13	88%	70.7%
#721	Accounts Merge ArrayHash TableStringDepth-First SearchBreadth-First SearchUnion-FindSorting	Medium	Grab Docusign Meta ByteDance+13	83%	61.6%
#211	Design Add and Search Words Data Structure StringDepth-First SearchDesignTrie	Medium	Datadog NeetCode 150 Snowflake TikTok+12	88%	48.7%
#987	Vertical Order Traversal of a Binary Tree Hash TableTreeDepth-First SearchBreadth-First SearchSortingBinary Tree	Hard	Samsung Roku Meta BitGo+11	100%	54.2%
#130	Surrounded Regions ArrayDepth-First SearchBreadth-First SearchUnion-FindMatrix	Medium	Pornhub Moloco NeetCode 150 Nutanix+11	87%	0.5%
#417	Pacific Atlantic Water Flow ArrayDepth-First SearchBreadth-First SearchMatrix	Medium	Urban Company ServiceNow NeetCode 150 Flipkart+10	100%	61.2%
#235	Lowest Common Ancestor of a Binary Search Tree	Medium	X X NeetCode 150 LinkedIn+10	100%	70.9%
#230	Kth Smallest Element in a BST TreeDepth-First SearchBinary Search TreeBinary Tree	Medium	Uber NeetCode 150 Expedia Oracle+10	88%	77.0%
#490	The Maze ArrayDepth-First SearchBreadth-First SearchMatrix	Medium	Uber Walmart Labs Snap Meta+10	63%	60.5%
#2603	Collect Coins in a Tree ArrayTreeGraph TheoryTopological Sort	Hard	Lucid Cisco Graviton Millennium+9	100%	39.5%
#2385	Amount of Time for Binary Tree to Be Infected Hash TableTreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	blinkit ShareChat ServiceNow PhonePe+9	100%	65.7%
#694	Number of Distinct Islands ArrayHash TableDepth-First SearchBreadth-First SearchUnion-FindSortingMatrixHash Function	Medium	Snap TikTok Snap Coupang+9	92%	62.9%
#337	House Robber III Dynamic ProgrammingTreeDepth-First SearchBinary TreeDP on Trees	Medium	oyo Docusign ZIP Two Sigma+9	88%	56.1%
#733	Flood Fill ArrayDepth-First SearchBreadth-First SearchMatrix	Easy	Criteo Qualtrics Amazon Apple+9	88%	68.6%
#642	Design Search Autocomplete System StringDepth-First SearchDesignTrieSortingHeap (Priority Queue)Data Stream	Hard	Roblox Pinterest MongoDB Netflix+9	75%	50.0%
#105	Construct Binary Tree from Preorder and Inorder Traversal ArrayHash TableDivide and ConquerTreeBinary Tree	Medium	NeetCode 150 TikTok Media.net Adobe+8	83%	69.1%
#886	Possible Bipartition Depth-First SearchBreadth-First SearchUnion-FindGraph TheoryGraph ColoringBipartite Graph	Medium	Samsung Meesho TikTok LinkedIn+8	75%	52.8%
#101	Symmetric Tree TreeDepth-First SearchBreadth-First SearchBinary Tree	Easy	VK LinkedIn Yandex Bloomberg+8	66%	61.6%
#110	Balanced Binary Tree TreeDepth-First SearchBinary Tree	Easy	Viasat NeetCode 150 Bloomberg Anduril+7	100%	58.7%
#261	Graph Valid Tree Depth-First SearchBreadth-First SearchUnion-FindGraph Theory	Medium	Zenefits NeetCode 150 LinkedIn Snowflake+7	100%	50.1%
#1319	Number of Operations to Make Network Connected Depth-First SearchBreadth-First SearchUnion-FindGraph Theory	Medium	Akuna Capital PhonePe IBM PayPal+7	100%	66.9%
#743	Network Delay Time Depth-First SearchBreadth-First SearchGraph TheoryHeap (Priority Queue)Shortest PathDijkstra's Algorithm	Medium	Akuna Capital Netflix NeetCode 150 Salesforce+7	100%	61.0%
#314	Binary Tree Vertical Order Traversal Hash TableTreeDepth-First SearchBreadth-First SearchSortingBinary Tree	Medium	Meta Snap Snap Bloomberg+7	93%	57.9%
#572	Subtree of Another Tree TreeDepth-First SearchString MatchingBinary TreeHash Function	Easy	eBay Jump Trading NeetCode 150 Compass+7	89%	51.9%
#1650	Lowest Common Ancestor of a Binary Tree III Hash TableTwo PointersTreeBinary TreeBinary LiftingLowest Common Ancestor	Medium	Meta LinkedIn MongoDB Wix+7	89%	83.0%
#785	Is Graph Bipartite? Depth-First SearchBreadth-First SearchUnion-FindGraph TheoryGraph ColoringBipartite Graph	Medium	Lime Samsung LinkedIn Meta+7	88%	59.6%
#96	Unique Binary Search Trees MathDynamic ProgrammingTreeBinary Search TreeBinary Tree	Medium	Snap Snap Clari Swiggy+7	88%	63.9%
#1192	Critical Connections in a Network Depth-First SearchGraph TheoryBiconnected ComponentBridge (Graph)	Hard	KLA Tencor InMobi Akuna Capital ServiceNow+7	88%	0.6%
#226	Invert Binary Tree TreeDepth-First SearchBreadth-First SearchBinary Tree	Easy	NeetCode 150 Josh Technology Palo Alto Networks Google+7	87%	80.2%
#100	Same Tree TreeDepth-First SearchBreadth-First SearchBinary Tree	Easy	NeetCode 150 SAP Bloomberg Amazon+7	85%	67.5%
#778	Swim in Rising Water ArrayBinary SearchDepth-First SearchBreadth-First SearchUnion-FindMinimaxHeap (Priority Queue)MatrixDijkstra's Algorithm	Hard	WeRide NeetCode 150 Meta Google+7	78%	68.0%
#2858	Minimum Edge Reversals So Every Node Is Reachable Dynamic ProgrammingDepth-First SearchBreadth-First SearchGraph Theory	Hard	Uber MathWorks Meesho Cashfree+7	77%	60.0%
#437	Path Sum III TreeDepth-First SearchBinary Tree	Medium	Millennium NetApp Zepto TikTok+7	76%	46.5%
#684	Redundant Connection Depth-First SearchBreadth-First SearchUnion-FindGraph Theory	Medium	Box NeetCode 150 InMobi Bloomberg+7	75%	0.7%
#450	Delete Node in a BST TreeBinary Search TreeBinary Tree	Medium	Oracle Uber ByteDance Flipkart+7	53%	55.0%
#841	Keys and Rooms Depth-First SearchBreadth-First SearchGraph Theory	Medium	Cadence Graviton Snowflake Apple+6	100%	76.0%
#109	Convert Sorted List to Binary Search Tree Linked ListDivide and ConquerTreeBinary Search TreeBinary Tree	Medium	Zenefits Lyft Salesforce Meta+6	100%	66.9%
#323	Number of Connected Components in an Undirected Graph Depth-First SearchBreadth-First SearchUnion-FindGraph Theory	Medium	X General Motors X NeetCode 150+6	100%	65.1%
#924	Minimize Malware Spread ArrayHash TableDepth-First SearchBreadth-First SearchUnion-FindGraph Theory	Hard	Dropbox NCR BNY Mellon Salesforce+6	100%	43.3%
#1202	Smallest String With Swaps ArrayHash TableStringDepth-First SearchBreadth-First SearchUnion-FindSorting	Medium	PhonePe PayPal Palantir Rubrik+6	100%	60.8%
#113	Path Sum II BacktrackingTreeDepth-First SearchBinary Tree	Medium	Arista Networks Palo Alto Networks Flipkart Meta+6	63%	62.5%
#545	Boundary of Binary Tree TreeDepth-First SearchBinary Tree	Medium	Snowflake Nutanix Meta Uber+6	63%	48.2%
#1743	Restore the Array From Adjacent Pairs ArrayHash TableDepth-First Search	Medium	Robinhood SIG Capital One eBay+5	100%	75.1%
#1242	Web Crawler Multithreaded Depth-First SearchBreadth-First SearchConcurrency	Medium	Dropbox Anthropic MongoDB Snowflake+5	100%	51.3%
#547	Number of Provinces Depth-First SearchBreadth-First SearchUnion-FindGraph Theory	Medium	Two Sigma Bloomberg Amazon Adobe+5	100%	70.7%
#1448	Count Good Nodes in Binary Tree TreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	NeetCode 150 Josh Technology Docusign Microsoft+5	84%	73.9%
#529	Minesweeper ArrayDepth-First SearchBreadth-First SearchMatrix	Medium	Robinhood Applied Intuition Nuro Anduril+5	78%	68.8%
#108	Convert Sorted Array to Binary Search Tree ArrayDivide and ConquerTreeBinary Search TreeBinary Tree	Easy	Airbnb Accenture Amazon Apple+5	75%	75.8%
#1631	Path With Minimum Effort ArrayBinary SearchDepth-First SearchBreadth-First SearchUnion-FindHeap (Priority Queue)MatrixDijkstra's Algorithm	Medium	Waymo Nutanix Visa Snowflake+5	67%	63.6%
#463	Island Perimeter ArrayDepth-First SearchBreadth-First SearchMatrix	Easy	Zoho Josh Technology Oracle Apple+5	63%	74.5%
#652	Find Duplicate Subtrees Hash TableTreeDepth-First SearchBinary Tree	Medium	Yandex PhonePe Google Salesforce+5	63%	60.8%
#112	Path Sum TreeDepth-First SearchBreadth-First SearchBinary Tree	Easy	Palo Alto Networks Microsoft Apple Amazon+5	51%	55.3%
#419	Battleships in a Board ArrayDepth-First SearchMatrix	Medium	HSBC Tinkoff Microstrategy Meta+4	100%	77.6%
#257	Binary Tree Paths StringBacktrackingTreeDepth-First SearchBinary Tree	Easy	Revolut Capital One Apple Meta+4	89%	69.0%
#1233	Remove Sub-Folders from the Filesystem ArrayStringDepth-First SearchTrie	Medium	Verkada Nuro Snowflake Google+4	88%	78.6%
#270	Closest Binary Search Tree Value Binary SearchTreeDepth-First SearchBinary Search TreeBinary Tree	Easy	Snap Snap Meta Fractal Analytics+4	88%	49.2%
#653	Two Sum IV - Input is a BST Hash TableTwo PointersTreeDepth-First SearchBreadth-First SearchBinary Search TreeBinary Tree	Easy	Samsung Meta Cisco Amazon+4	88%	63.5%
#427	Construct Quad Tree ArrayDivide and ConquerTreeMatrix	Medium	Uber Palantir Snowflake Google+4	88%	78.5%
#931	Minimum Falling Path Sum ArrayDynamic ProgrammingMatrix	Medium	Dream11 Goldman Sachs Amazon Google+4	67%	60.9%
#979	Distribute Coins in Binary Tree TreeDepth-First SearchBinary TreeDP on Trees	Medium	Zeta Global Goldman Sachs tcs Amazon+4	64%	77.3%
#173	Binary Search Tree Iterator StackTreeDesignBinary Search TreeBinary TreeIterator	Medium	Meta LinkedIn Microsoft Amazon+4	63%	76.7%
#617	Merge Two Binary Trees TreeDepth-First SearchBreadth-First SearchBinary Tree	Easy	Josh Technology MongoDB LinkedIn Amazon+4	63%	79.1%
#662	Maximum Width of Binary Tree TreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	ByteDance Flipkart Amazon TikTok+4	63%	45.8%
#116	Populating Next Right Pointers in Each Node Linked ListTreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Walmart Labs Bloomberg Meta Amazon+4	53%	67.4%
#515	Find Largest Value in Each Tree Row TreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Josh Technology LinkedIn Apple Bloomberg+4	52%	66.3%
#365	Water and Jug Problem MathDepth-First SearchBreadth-First SearchBézout's LemmaEuclidean AlgorithmGreatest Common DivisorExtended Euclidean Algorithm	Medium	Lyft TikTok Microsoft Uber+4	51%	45.9%
#2196	Create Binary Tree From Descriptions ArrayHash TableTreeBinary Tree	Medium	Clari LinkedIn Uber Amazon+3	100%	83.9%
#310	Minimum Height Trees Depth-First SearchBreadth-First SearchGraph TheoryTopological Sort	Medium	Stackline Splunk Google Amazon+3	100%	42.6%
#111	Minimum Depth of Binary Tree TreeDepth-First SearchBreadth-First SearchBinary Tree	Easy	Livspace Bloomberg tcs Meta+3	100%	53.3%
#1236	Web Crawler StringDepth-First SearchBreadth-First SearchInteractive	Medium	Dropbox Anthropic Snowflake Rubrik+3	100%	68.8%
#2360	Longest Cycle in a Graph Depth-First SearchBreadth-First SearchGraph TheoryTopological SortKosaraju's AlgorithmTarjan's SCC Algorithm	Hard	Juspay PhonePe Anduril Nvidia+3	88%	50.9%
#513	Find Bottom Left Tree Value TreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Gopuff Josh Technology Microsoft Bloomberg+3	88%	72.4%
#2101	Detonate the Maximum Bombs ArrayMathDepth-First SearchBreadth-First SearchGraph TheoryGeometry	Medium	Chime Lyft Airbnb Uber+3	88%	50.3%
#1948	Delete Duplicate Folders in System ArrayHash TableStringDepth-First SearchTrieSortingHash Function	Hard	Booking.com Booking.com Nvidia Amazon+3	88%	77.4%
#834	Sum of Distances in Tree Dynamic ProgrammingTreeDepth-First SearchGraph TheoryDP on Trees	Hard	PhonePe Google Uber Meta+3	85%	65.7%
#430	Flatten a Multilevel Doubly Linked List Linked ListDepth-First SearchDoubly-Linked List	Medium	Bloomberg Adobe Amazon LinkedIn+3	79%	63.1%
#129	Sum Root to Leaf Numbers TreeDepth-First SearchBinary Tree	Medium	Meta Visa Oracle Google+3	78%	70.1%
#3607	Power Grid Maintenance ArrayHash TableDepth-First SearchBreadth-First SearchUnion-FindGraph TheoryHeap (Priority Queue)Ordered Set	Medium	Cisco Salesforce Zeta Global Meta+3	75%	56.1%
#222	Count Complete Tree Nodes Binary SearchBit ManipulationTreeBinary Tree	Medium	Dunzo Adobe Google Meta+3	68%	73.1%
#851	Loud and Rich ArrayDepth-First SearchGraph TheoryTopological SortDirected Acyclic Graph	Medium	PhonePe PayPal Flipkart DE Shaw+3	65%	63.8%
#765	Couples Holding Hands GreedyDepth-First SearchBreadth-First SearchUnion-FindGraph Theory	Hard	Citadel Squarepoint Capital Palo Alto Networks Bloomberg+3	63%	0.6%
#701	Insert into a Binary Search Tree TreeBinary Search TreeBinary Tree	Medium	Anduril Microsoft Amazon LinkedIn+3	63%	73.5%
#106	Construct Binary Tree from Inorder and Postorder Traversal ArrayHash TableDivide and ConquerTreeBinary Tree	Medium	Walmart Labs Microsoft TikTok Amazon+3	63%	69.1%
#94	Binary Tree Inorder Traversal StackTreeDepth-First SearchBinary Tree	Easy	Anduril Microsoft Bloomberg Google+3	50%	80.3%
#802	Find Eventual Safe States Depth-First SearchBreadth-First SearchGraph TheoryTopological SortKosaraju's AlgorithmTarjan's SCC Algorithm	Medium	Citadel Amazon Google Bloomberg+3	50%	71.2%
#117	Populating Next Right Pointers in Each Node II Linked ListTreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Bloomberg Meta Microsoft Snowflake+3	50%	57.8%
#428	Serialize and Deserialize N-ary Tree StringTreeDepth-First SearchBreadth-First Search	Hard	Apple Nvidia TikTok Bloomberg+3	39%	68.9%
#1245	Tree Diameter TreeDepth-First SearchBreadth-First SearchGraph TheoryTopological SortDP on Trees	Medium	TikTok Salesforce Meta Goldman Sachs+3	39%	61.3%
#1559	Detect Cycles in 2D Grid ArrayDepth-First SearchBreadth-First SearchUnion-FindMatrix	Medium	Nutanix WeRide Amazon Google+2	100%	63.4%
#285	Inorder Successor in BST TreeDepth-First SearchBinary Search TreeBinary Tree	Medium	Pocket Gems Docusign Microsoft Meta+2	100%	51.2%
#2246	Longest Path With Different Adjacent Characters ArrayStringTreeDepth-First SearchGraph TheoryTopological Sort	Hard	Hudson River Trading Hudson River Trading Target Microsoft+2	100%	0.5%
#2791	Count Paths That Can Form a Palindrome in a Tree Hash TableBit ManipulationTreeDepth-First Search	Hard	thoughtspot WeRide Uber Goldman Sachs+2	100%	0.5%
#339	Nested List Weight Sum Depth-First SearchBreadth-First Search	Medium	Meta LinkedIn Adobe Oracle+2	88%	86.0%
#2096	Step-By-Step Directions From a Binary Tree Node to Another StringTreeDepth-First SearchBinary TreeBinary LiftingLowest Common Ancestor	Medium	Databricks Snowflake TikTok Google+2	88%	56.5%
#1022	Sum of Root To Leaf Binary Numbers TreeDepth-First SearchBinary Tree	Easy	Lime Amazon Bloomberg Meta+2	88%	76.6%
#2467	Most Profitable Path in a Tree ArrayTreeDepth-First SearchBreadth-First SearchGraph Theory	Medium	Intuit Uber Snowflake Meta+2	88%	67.3%
#938	Range Sum of BST TreeDepth-First SearchBinary Search TreeBinary Tree	Easy	Meta Yandex Google Bloomberg+2	78%	87.6%
#366	Find Leaves of Binary Tree TreeDepth-First SearchBinary TreeDP on Trees	Medium	LinkedIn Oracle Flipkart Salesforce+2	77%	81.3%
#690	Employee Importance ArrayHash TableTreeDepth-First SearchBreadth-First Search	Medium	Robinhood Uber Google Amazon+2	75%	69.6%
#404	Sum of Left Leaves TreeDepth-First SearchBreadth-First SearchBinary Tree	Easy	Grammarly Meta Microsoft Amazon+2	75%	62.9%
#1028	Recover a Tree From Preorder Traversal StringTreeDepth-First SearchBinary Tree	Hard	Grammarly Amazon Google Microsoft+2	70%	83.3%
#2493	Divide Nodes Into the Maximum Number of Groups Depth-First SearchBreadth-First SearchUnion-FindGraph Theory	Hard	Uber Accenture Google Meta+2	63%	66.9%
#386	Lexicographical Numbers Depth-First SearchTrie	Medium	Barclays Bloomberg Google Amazon+2	53%	76.3%
#993	Cousins in Binary Tree TreeDepth-First SearchBreadth-First SearchBinary Tree	Easy	Adobe Bloomberg Amazon Meta+2	52%	59.5%
#872	Leaf-Similar Trees TreeDepth-First SearchBinary Tree	Easy	Snowflake Meta Amazon Microsoft+2	50%	70.3%
#1462	Course Schedule IV Depth-First SearchBreadth-First SearchGraph TheoryTopological Sort	Medium	TikTok Uber Amazon Meta+2	50%	60.0%
#1008	Construct Binary Search Tree from Preorder Traversal ArrayStackTreeBinary Search TreeMonotonic StackBinary Tree	Medium	Amazon Salesforce Meta Microsoft+2	38%	84.4%
#1020	Number of Enclaves ArrayDepth-First SearchBreadth-First SearchUnion-FindMatrix	Medium	Google Bloomberg Microsoft Uber+2	27%	72.0%
#700	Search in a Binary Search Tree TreeBinary Search TreeBinary Tree	Easy	Google Meta Amazon Microsoft+2	25%	82.9%
#107	Binary Tree Level Order Traversal II TreeBreadth-First SearchBinary Tree	Medium	Oracle Bloomberg Amazon Meta+2	25%	68.6%
#889	Construct Binary Tree from Preorder and Postorder Traversal ArrayHash TableDivide and ConquerTreeBinary Tree	Medium	Apple Google Bloomberg Meta+2	25%	78.1%
#1267	Count Servers that Communicate ArrayDepth-First SearchBreadth-First SearchUnion-FindMatrixCounting	Medium	Oracle Amazon Microsoft Google+2	25%	73.5%
#1367	Linked List in Binary Tree Linked ListTreeDepth-First SearchBinary Tree	Medium	SoundHound Meta Amazon Bloomberg+1	100%	52.0%
#814	Binary Tree Pruning TreeDepth-First SearchBinary Tree	Medium	Hulu Meta Microsoft Amazon+1	100%	72.5%
#655	Print Binary Tree TreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Poynt Google Meta Amazon+1	100%	66.7%
#255	Verify Preorder Sequence in Binary Search Tree ArrayStackTreeBinary Search TreeRecursionMonotonic StackBinary Tree	Medium	Zenefits Expedia Salesforce TikTok+1	100%	51.8%
#958	Check Completeness of a Binary Tree TreeBreadth-First SearchBinary Tree	Medium	Lyft Meta Microsoft Amazon+1	75%	59.3%
#1026	Maximum Difference Between Node and Ancestor TreeDepth-First SearchBinary Tree	Medium	Josh Technology EPAM Systems Amazon Meta+1	63%	78.2%
#1443	Minimum Time to Collect All Apples in a Tree Hash TableTreeDepth-First SearchBreadth-First SearchDP on Trees	Medium	Cisco PhonePe Meta Microsoft+1	63%	63.8%
#797	All Paths From Source to Target BacktrackingDepth-First SearchBreadth-First SearchGraph TheoryDirected Acyclic Graph	Medium	Bloomberg Netflix Amazon Meta+1	63%	83.7%
#2316	Count Unreachable Pairs of Nodes in an Undirected Graph Depth-First SearchBreadth-First SearchUnion-FindGraph Theory	Medium	Snap Snap Amazon Microsoft+1	63%	0.5%
#2127	Maximum Employees to Be Invited to a Meeting ArrayDynamic ProgrammingDepth-First SearchGraph TheoryTopological SortKosaraju's AlgorithmTarjan's SCC Algorithm	Hard	Nutanix Microsoft Oracle Google+1	60%	61.8%
#1203	Sort Items by Groups Respecting Dependencies Depth-First SearchBreadth-First SearchGraph TheoryTopological SortDirected Acyclic Graph	Hard	Citadel Meta Amazon Bloomberg+1	56%	66.0%
#505	The Maze II ArrayDepth-First SearchBreadth-First SearchGraph TheoryHeap (Priority Queue)MatrixShortest PathDijkstra's AlgorithmHeuristic SearchA* Search	Medium	Uber TikTok Google Meta+1	54%	55.2%
#1466	Reorder Routes to Make All Paths Lead to the City Zero Depth-First SearchBreadth-First SearchGraph Theory	Medium	TikTok Microsoft Amazon Meta+1	50%	66.0%
#2583	Kth Largest Sum in a Binary Tree TreeBreadth-First SearchSortingBinary Tree	Medium	Visa Amazon Bloomberg Microsoft+1	39%	59.0%
#839	Similar String Groups ArrayHash TableStringDepth-First SearchBreadth-First SearchUnion-Find	Hard	DoorDash Apple Google Meta+1	38%	56.4%
#1382	Balance a Binary Search Tree Divide and ConquerGreedyTreeDepth-First SearchBinary Search TreeBinary Tree	Medium	Amazon Meta Microsoft Bloomberg+1	38%	86.3%
#1971	Find if Path Exists in Graph Depth-First SearchBreadth-First SearchUnion-FindGraph Theory	Easy	Bloomberg Microsoft Amazon Google+1	38%	55.5%
#1254	Number of Closed Islands ArrayDepth-First SearchBreadth-First SearchUnion-FindMatrix	Medium	Oracle Google Microsoft Meta+1	38%	67.2%
#1373	Maximum Sum BST in Binary Tree Dynamic ProgrammingTreeDepth-First SearchBinary Search TreeBinary TreeDP on Trees	Hard	Amazon Google Microsoft Meta+1	38%	48.1%
#1339	Maximum Product of Splitted Binary Tree TreeDepth-First SearchBinary Tree	Medium	Microsoft Amazon Google Meta+1	38%	55.8%
#2477	Minimum Fuel Cost to Report to the Capital TreeDepth-First SearchBreadth-First SearchGraph Theory	Medium	Microsoft Amazon Uber Meta+1	38%	65.4%
#894	All Possible Full Binary Trees Dynamic ProgrammingTreeRecursionMemoizationBinary Tree	Medium	Nvidia Salesforce Google Amazon+1	38%	82.8%
#95	Unique Binary Search Trees II Dynamic ProgrammingBacktrackingTreeBinary Search TreeBinary Tree	Medium	Meta Amazon Google Bloomberg+1	28%	62.8%
#144	Binary Tree Preorder Traversal StackTreeDepth-First SearchBinary Tree	Easy	Google Amazon Bloomberg Microsoft+1	27%	76.2%
#145	Binary Tree Postorder Traversal StackTreeDepth-First SearchBinary Tree	Easy	Amazon Bloomberg Google Meta+1	25%	78.5%
#2236	Root Equals Sum of Children TreeBinary Tree	Easy	Google Amazon Meta Bloomberg+1	25%	85.1%
#965	Univalued Binary Tree TreeDepth-First SearchBreadth-First SearchBinary Tree	Easy	Twilio Box Google Amazon	100%	73.2%
#3068	Find the Maximum Sum of Node Values ArrayDynamic ProgrammingGreedyBit ManipulationTreeSorting	Hard	Deutsche Bank BlackRock Meta Google	100%	69.4%
#3203	Find Minimum Diameter After Merging Two Trees TreeDepth-First SearchBreadth-First SearchGraph Theory	Hard	ServiceNow Oracle Microsoft Google	100%	57.0%
#1306	Jump Game III ArrayDepth-First SearchBreadth-First Search	Medium	Tanium Microsoft Amazon Google	100%	70.3%
#1036	Escape a Large Maze ArrayHash TableDepth-First SearchBreadth-First SearchBidirectional Search	Hard	UiPath Amazon Microsoft Google	100%	36.8%
#783	Minimum Distance Between BST Nodes TreeDepth-First SearchBreadth-First SearchBinary Search TreeBinary Tree	Easy	Wix Google Meta Amazon	88%	61.6%
#1034	Coloring A Border ArrayDepth-First SearchBreadth-First SearchMatrix	Medium	Booking.com Booking.com Microsoft Google	88%	0.5%
#250	Count Univalue Subtrees TreeDepth-First SearchBinary TreeDP on Trees	Medium	6sense Zeta Global Amazon Google	88%	57.5%
#2359	Find Closest Node to Given Two Nodes Depth-First SearchGraph Theory	Medium	Juspay Amazon Bloomberg Google	88%	53.1%
#1722	Minimize Hamming Distance After Swap Operations ArrayDepth-First SearchUnion-Find	Medium	Sumo Logic Sumo Logic Google Bloomberg	79%	0.7%
#385	Mini Parser StringStackDepth-First Search	Medium	Airbnb Meta Amazon Bloomberg	75%	42.9%
#449	Serialize and Deserialize BST StringTreeDepth-First SearchBreadth-First SearchDesignBinary Search TreeBinary Tree	Medium	Shopee Amazon Microsoft Google	68%	59.8%
#1325	Delete Leaves With a Given Value TreeDepth-First SearchBinary Tree	Medium	Josh Technology Amazon Microsoft Google	67%	77.2%
#426	Convert Binary Search Tree to Sorted Doubly Linked List Linked ListStackTreeDepth-First SearchBinary Search TreeBinary TreeDoubly-Linked List	Medium	Meta TikTok Amazon Microsoft	64%	65.6%
#1315	Sum of Nodes with Even-Valued Grandparent TreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Josh Technology Salesforce Amazon Meta	63%	86.0%
#1110	Delete Nodes And Return Forest ArrayHash TableTreeDepth-First SearchBinary Tree	Medium	Pinterest Google Meta Amazon	63%	72.5%
#2192	All Ancestors of a Node in a Directed Acyclic Graph Depth-First SearchBreadth-First SearchGraph TheoryTopological SortDirected Acyclic Graph	Medium	Oracle Google Amazon Meta	63%	62.3%
#1676	Lowest Common Ancestor of a Binary Tree IV Hash TableTreeDepth-First SearchBinary TreeBinary LiftingLowest Common Ancestor	Medium	Atlassian Amazon TikTok Meta	63%	79.6%
#2265	Count Nodes Equal to Average of Subtree TreeDepth-First SearchBinary Tree	Medium	Meta Snowflake Amazon Google	53%	86.8%
#1644	Lowest Common Ancestor of a Binary Tree II TreeDepth-First SearchBinary TreeBinary LiftingLowest Common Ancestor	Medium	LinkedIn Meta Atlassian Microsoft	51%	69.7%
#737	Sentence Similarity II ArrayHash TableStringDepth-First SearchBreadth-First SearchUnion-Find	Medium	Rippling Apple Google Amazon	50%	51.4%
#298	Binary Tree Longest Consecutive Sequence TreeDepth-First SearchBinary TreeDP on Trees	Medium	TikTok Google Meta Amazon	50%	54.8%
#669	Trim a Binary Search Tree TreeDepth-First SearchBinary Search TreeBinary Tree	Medium	Adobe Bloomberg Amazon Google	42%	66.8%
#1970	Last Day Where You Can Still Cross ArrayBinary SearchDepth-First SearchBreadth-First SearchUnion-FindMatrix	Hard	Atlassian Google Meta Amazon	41%	68.7%
#582	Kill Process ArrayHash TableTreeDepth-First SearchBreadth-First Search	Medium	Oracle Bloomberg Amazon Microsoft	39%	70.7%
#865	Smallest Subtree with all the Deepest Nodes Hash TableTreeDepth-First SearchBreadth-First SearchBinary TreeBinary LiftingLowest Common AncestorDP on Trees	Medium	Meta Bloomberg Amazon Google	39%	77.6%
#1123	Lowest Common Ancestor of Deepest Leaves Hash TableTreeDepth-First SearchBreadth-First SearchBinary TreeBinary LiftingLowest Common AncestorDP on Trees	Medium	Meta Google Bloomberg Amazon	38%	79.5%
#2872	Maximum Number of K-Divisible Components TreeDepth-First Search	Hard	Infosys Google Amazon Microsoft	38%	74.0%
#1161	Maximum Level Sum of a Binary Tree TreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Google Meta Microsoft Amazon	28%	70.0%
#654	Maximum Binary Tree ArrayDivide and ConquerStackTreeMonotonic StackBinary TreeCartesian Tree	Medium	Microsoft Meta Google Bloomberg	27%	86.4%
#1483	Kth Ancestor of a Tree Node Binary SearchDynamic ProgrammingBit ManipulationTreeDepth-First SearchBreadth-First SearchDesignBinary Lifting	Hard	Google Goldman Sachs Amazon Bloomberg	27%	38.9%
#388	Longest Absolute File Path StringStackDepth-First Search	Medium	Google Meta Amazon Microsoft	26%	49.6%
#501	Find Mode in Binary Search Tree TreeDepth-First SearchBinary Search TreeBinary Tree	Easy	Google Meta Amazon Bloomberg	25%	59.1%
#637	Average of Levels in Binary Tree TreeDepth-First SearchBreadth-First SearchBinary Tree	Easy	Meta Amazon Microsoft Google	25%	75.0%
#538	Convert BST to Greater Tree TreeDepth-First SearchBinary Search TreeBinary Tree	Medium	Amazon Microsoft Meta Google	25%	71.8%
#2322	Minimum Score After Removals on a Tree ArrayBit ManipulationTreeDepth-First Search	Hard	Amazon Meta Microsoft Google	25%	76.1%
#1289	Minimum Falling Path Sum II ArrayDynamic ProgrammingMatrix	Hard	Google Meta Bloomberg Microsoft	25%	63.0%
#2685	Count the Number of Complete Components Depth-First SearchBreadth-First SearchUnion-FindGraph Theory	Medium	Microsoft Meta Amazon Google	16%	80.8%
#2658	Maximum Number of Fish in a Grid ArrayDepth-First SearchBreadth-First SearchUnion-FindMatrix	Medium	Meta Amazon Microsoft Google	13%	70.3%
#364	Nested List Weight Sum II StackDepth-First SearchBreadth-First Search	Medium	LinkedIn Meta Google	100%	67.0%
#3367	Maximize Sum of Weights after Edge Removals Dynamic ProgrammingTreeDepth-First SearchSorting	Hard	Gameskraft Uber LinkedIn	100%	0.3%
#1391	Check if There is a Valid Path in a Grid ArrayDepth-First SearchBreadth-First SearchUnion-FindMatrix	Medium	Robinhood Samsung Google	100%	64.5%
#563	Binary Tree Tilt TreeDepth-First SearchBinary TreeDP on Trees	Easy	Indeed Meta Amazon	100%	66.1%
#3067	Count Pairs of Connectable Servers in a Weighted Tree Network ArrayTreeDepth-First Search	Medium	UBS thoughtspot Rippling	100%	56.2%
#1993	Operations on Tree ArrayHash TableTreeDepth-First SearchBreadth-First SearchDesign	Medium	Juspay Google Amazon	100%	45.7%
#2471	Minimum Number of Operations to Sort a Binary Tree by Level TreeBreadth-First SearchBinary Tree	Medium	Guidewire Amazon Google	100%	74.3%
#749	Contain Virus ArrayDepth-First SearchBreadth-First SearchMatrixSimulation	Hard	Flipkart Bloomberg Google	100%	55.1%
#623	Add One Row to Tree TreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Gilt Groupe Bloomberg Google	100%	64.2%
#3715	Sum of Perfect Square Ancestors ArrayHash TableMathTreeDepth-First SearchCountingNumber Theory	Hard	Meesho Amazon Google	92%	42.8%
#510	Inorder Successor in BST II TreeBinary Search TreeBinary Tree	Medium	Arista Networks Meta Google	78%	61.1%
#1302	Deepest Leaves Sum TreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Myntra TikTok Google	75%	86.6%
#2049	Count Nodes With the Highest Score ArrayTreeDepth-First SearchBinary TreeDP on Trees	Medium	Visa DoorDash Amazon	75%	52.9%
#1102	Path With Maximum Minimum Value ArrayBinary SearchDepth-First SearchBreadth-First SearchUnion-FindHeap (Priority Queue)MatrixDijkstra's Algorithm	Medium	Geico Google Amazon	68%	54.7%
#272	Closest Binary Search Tree Value II Two PointersStackTreeDepth-First SearchBinary Search TreeHeap (Priority Queue)Binary Tree	Hard	LinkedIn Google Amazon	63%	61.2%
#671	Second Minimum Node In a Binary Tree TreeDepth-First SearchBinary Tree	Easy	LinkedIn Meta Amazon	63%	46.2%
#742	Closest Leaf in a Binary Tree TreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Databricks LinkedIn Amazon	63%	47.5%
#3387	Maximize Amount After Two Days of Conversions ArrayStringDepth-First SearchBreadth-First SearchGraph Theory	Medium	Rippling Uber Google	60%	61.7%
#1038	Binary Search Tree to Greater Sum Tree TreeDepth-First SearchBinary Search TreeBinary Tree	Medium	SAP Amazon Google	56%	88.4%
#514	Freedom Trail StringDynamic ProgrammingDepth-First SearchBreadth-First Search	Hard	PhonePe Uber Google	54%	59.4%
#472	Concatenated Words ArrayStringDynamic ProgrammingDepth-First SearchTrieSorting	Hard	Amazon eBay TikTok	53%	49.9%
#565	Array Nesting ArrayDepth-First Search	Medium	Apple Amazon Google	51%	56.7%
#536	Construct Binary Tree from String StringStackTreeDepth-First SearchBinary Tree	Medium	Meta Amazon Bloomberg	50%	58.7%
#1530	Number of Good Leaf Nodes Pairs TreeDepth-First SearchBinary TreeDP on Trees	Medium	ByteDance TikTok Google	50%	71.8%
#2097	Valid Arrangement of Pairs ArrayDepth-First SearchGraph TheoryEulerian CircuitEulerian PathSemi-Eulerian Graph	Hard	Goldman Sachs Amazon Google	50%	66.6%
#1778	Shortest Path in a Hidden Grid ArrayDepth-First SearchBreadth-First SearchMatrixInteractive	Medium	Meta Bloomberg Google	40%	44.7%
#1522	Diameter of N-Ary Tree TreeDepth-First SearchDP on Trees	Medium	Salesforce Meta Goldman Sachs	38%	75.5%
#1609	Even Odd Tree TreeBreadth-First SearchBinary Tree	Medium	Bloomberg Meta Amazon	38%	67.2%
#2458	Height of Binary Tree After Subtree Removal Queries ArrayTreeDepth-First SearchBreadth-First SearchBinary Tree	Hard	Snowflake Google Meta	38%	54.9%
#530	Minimum Absolute Difference in BST TreeDepth-First SearchBreadth-First SearchBinary Search TreeBinary Tree	Easy	Google Meta Amazon	29%	59.5%
#508	Most Frequent Subtree Sum Hash TableTreeDepth-First SearchBinary TreeDP on Trees	Medium	Amazon Bloomberg Microsoft	27%	69.4%
#1361	Validate Binary Tree Nodes TreeDepth-First SearchBreadth-First SearchUnion-FindGraph TheoryBinary Tree	Medium	Meta Microsoft Google	25%	44.2%
#2596	Check Knight Tour Configuration ArrayDepth-First SearchBreadth-First SearchMatrixSimulation	Medium	Meta Amazon Google	25%	61.7%
#606	Construct String from Binary Tree StringTreeDepth-First SearchBinary Tree	Medium	TikTok Amazon Meta	25%	70.8%
#1506	Find Root of N-Ary Tree Hash TableBit ManipulationTreeDepth-First Search	Medium	Bloomberg Google Meta	25%	78.6%
#549	Binary Tree Longest Consecutive Sequence II TreeDepth-First SearchBinary TreeDP on Trees	Medium	Uber Google Meta	25%	50.1%
#919	Complete Binary Tree Inserter TreeBreadth-First SearchDesignBinary Tree	Medium	Google Meta Amazon	25%	65.2%
#2421	Number of Good Paths ArrayHash TableTreeUnion-FindGraph TheorySorting	Hard	Google Amazon Bloomberg	25%	56.5%
#590	N-ary Tree Postorder Traversal StackTreeDepth-First Search	Easy	Bloomberg Amazon Google	13%	81.1%
#3559	Number of Ways to Assign Edge Weights II ArrayMathDynamic ProgrammingBit ManipulationTreeDepth-First Search	Hard	Bloomberg Amazon Google	13%	72.5%
#3310	Remove Methods From Project Depth-First SearchBreadth-First SearchGraph Theory	Medium	Bloomberg Amazon Google	13%	0.7%
#429	N-ary Tree Level Order Traversal TreeBreadth-First Search	Medium	Amazon Microsoft Google	13%	71.6%
#1932	Merge BSTs to Create Single BST ArrayHash TableTreeDepth-First SearchBinary Search TreeBinary Tree	Hard	Amazon Microsoft Google	13%	39.6%
#1992	Find All Groups of Farmland ArrayDepth-First SearchBreadth-First SearchMatrix	Medium	Citrix Google	100%	75.5%
#3372	Maximize the Number of Target Nodes After Connecting Trees I TreeDepth-First SearchBreadth-First Search	Medium	Jio Google	100%	69.4%
#3373	Maximize the Number of Target Nodes After Connecting Trees II TreeDepth-First SearchBreadth-First Search	Hard	Jio Google	100%	73.1%
#2368	Reachable Nodes With Restrictions ArrayHash TableTreeDepth-First SearchBreadth-First SearchUnion-FindGraph Theory	Medium	MakeMyTrip Google	100%	60.6%
#776	Split BST TreeBinary Search TreeRecursionBinary Tree	Medium	Coupang Amazon	100%	82.2%
#3123	Find Edges in Shortest Paths Depth-First SearchBreadth-First SearchGraph TheoryHeap (Priority Queue)Shortest Path	Hard	WeRide DoorDash	100%	46.9%
#928	Minimize Malware Spread II ArrayHash TableDepth-First SearchBreadth-First SearchUnion-FindGraph Theory	Hard	Dropbox Uber	100%	45.8%
#1457	Pseudo-Palindromic Paths in a Binary Tree Bit ManipulationTreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	BCG Amazon	100%	68.4%
#3710	Maximum Partition Factor ArrayBinary SearchDepth-First SearchBreadth-First SearchUnion-FindGraph Theory	Hard	Gameskraft Google	93%	32.1%
#1519	Number of Nodes in the Sub-Tree With the Same Label Hash TableTreeDepth-First SearchBreadth-First SearchCountingDP on Trees	Medium	Samsung Uber	88%	55.5%
#559	Maximum Depth of N-ary Tree TreeDepth-First SearchBreadth-First Search	Easy	Datadog Amazon	88%	73.7%
#1104	Path In Zigzag Labelled Binary Tree MathTreeBinary Tree	Medium	spinny Bloomberg	88%	75.8%
#2328	Number of Increasing Paths in a Grid ArrayDynamic ProgrammingDepth-First SearchBreadth-First SearchGraph TheoryTopological SortMemoizationMatrix	Hard	Adobe Microsoft	88%	57.3%
#1600	Throne Inheritance Hash TableTreeDepth-First SearchDesign	Medium	Snowflake Google	88%	67.4%
#1377	Frog Position After T Seconds TreeDepth-First SearchBreadth-First SearchGraph Theory	Hard	InMobi Google	83%	38.7%
#3619	Count Islands With Total Value Divisible by K ArrayDepth-First SearchBreadth-First SearchUnion-FindMatrix	Medium	Intuit Google	79%	56.2%
#156	Binary Tree Upside Down TreeDepth-First SearchBinary Tree	Medium	LinkedIn Google	75%	65.5%
#3004	Maximum Subtree of the Same Color ArrayDynamic ProgrammingTreeDepth-First Search	Medium	BlackRock Microsoft	75%	58.8%
#1724	Checking Existence of Edge Length Limited Paths II Depth-First SearchUnion-FindGraph TheoryDesignSortingHeap (Priority Queue)Minimum Spanning Tree	Hard	Oscar Health Google	75%	51.6%
#1042	Flower Planting With No Adjacent Depth-First SearchBreadth-First SearchGraph TheoryGraph Coloring	Medium	Vimeo Bloomberg	70%	53.9%
#2307	Check for Contradictions in Equations ArrayStringDepth-First SearchUnion-FindGraph Theory	Hard	Uber Amazon	50%	44.0%
#676	Implement Magic Dictionary Hash TableStringDepth-First SearchDesignTrie	Medium	Bloomberg Google	45%	58.0%
#2204	Distance to a Cycle in Undirected Graph Depth-First SearchBreadth-First SearchGraph TheoryTopological Sort	Hard	Oracle Microsoft	38%	73.9%
#1820	Maximum Number of Accepted Invitations ArrayDepth-First SearchGraph TheoryMatrixMaximum FlowMaximum MatchingBipartite GraphEdmonds–Karp AlgorithmMPM AlgorithmPush-Relabel AlgorithmMatching (Graph)Flow NetworkDinic's Algorithm	Medium	Bloomberg Google	38%	52.7%
#333	Largest BST Subtree Dynamic ProgrammingTreeDepth-First SearchBinary Search TreeBinary TreeDP on Trees	Medium	Microsoft Meta	27%	45.9%
#1810	Minimum Path Cost in a Hidden Grid ArrayDepth-First SearchBreadth-First SearchGraph TheoryHeap (Priority Queue)MatrixInteractiveShortest Path	Medium	Meta Google	27%	59.0%
#1485	Clone Binary Tree With Random Pointer Hash TableTreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Amazon Meta	27%	81.3%
#2641	Cousins in Binary Tree II Hash TableTreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Amazon Google	27%	75.9%
#711	Number of Distinct Islands II ArrayHash TableDepth-First SearchBreadth-First SearchUnion-FindSortingMatrixHash Function	Hard	Amazon Google	25%	55.5%
#1740	Find Distance in a Binary Tree Hash TableTreeDepth-First SearchBreadth-First SearchBinary TreeBinary LiftingLowest Common Ancestor	Medium	Apple Amazon	25%	74.4%
#1305	All Elements in Two Binary Search Trees TreeDepth-First SearchBinary Search TreeSortingBinary Tree	Medium	Amazon Meta	25%	80.3%
#988	Smallest String Starting From Leaf StringBacktrackingTreeDepth-First SearchBinary Tree	Medium	Google Amazon	25%	61.3%
#1145	Binary Tree Coloring Game TreeDepth-First SearchBinary Tree	Medium	Google Amazon	25%	53.0%
#1261	Find Elements in a Contaminated Binary Tree Hash TableTreeDepth-First SearchBreadth-First SearchDesignBinary Tree	Medium	Google Amazon	25%	84.1%
#3419	Minimize the Maximum Edge Weight of Graph Binary SearchDepth-First SearchBreadth-First SearchGraph TheoryShortest Path	Medium	Uber Google	25%	45.1%
#3593	Minimum Increments to Equalize Leaf Paths ArrayDynamic ProgrammingTreeDepth-First Search	Medium	Google Microsoft	16%	41.4%
#3558	Number of Ways to Assign Edge Weights I MathTreeDepth-First Search	Medium	Meta Amazon	13%	64.0%
#3562	Maximum Profit from Trading Stocks with Discounts ArrayDynamic ProgrammingTreeDepth-First Search	Hard	Meta Google	13%	56.5%
#897	Increasing Order Search Tree StackTreeDepth-First SearchBinary Search TreeBinary Tree	Easy	Amazon Google	13%	79.0%
#589	N-ary Tree Preorder Traversal StackTreeDepth-First Search	Easy	Amazon Google	13%	76.9%
#1372	Longest ZigZag Path in a Binary Tree Dynamic ProgrammingTreeDepth-First SearchBinary TreeDP on Trees	Medium	Amazon Microsoft	13%	67.3%
#3235	Check if the Rectangle Corner Is Reachable ArrayMathDepth-First SearchBreadth-First SearchUnion-FindGeometry	Hard	Amazon Google	13%	25.2%
#2876	Count Visited Nodes in a Directed Graph Dynamic ProgrammingDepth-First SearchGraph TheoryTopological SortMemoizationKosaraju's AlgorithmTarjan's SCC Algorithm	Hard	BNY Mellon	100%	31.1%
#2509	Cycle Length Queries in a Tree ArrayTreeBinary TreeBinary LiftingLowest Common Ancestor	Hard	Arcesium	100%	60.6%
#2440	Create Components With Same Value ArrayMathTreeDepth-First SearchEnumeration	Hard	Sprinklr	100%	53.7%
#666	Path Sum IV ArrayHash TableTreeDepth-First SearchBinary Tree	Medium	Alibaba	100%	62.9%
#2005	Subtree Removal Game with Fibonacci Tree MathDynamic ProgrammingTreeBinary TreeGame TheorySprague–Grundy Theorem	Hard	Sony	100%	57.8%
#2846	Minimum Edge Weight Equilibrium Queries in a Tree ArrayDynamic ProgrammingBit ManipulationTreeDepth-First Search	Hard	Sprinklr	90%	47.0%
#2378	Choose Edges to Maximize Score in a Tree Dynamic ProgrammingTreeDepth-First Search	Medium	Sprinklr	90%	56.8%
#1257	Smallest Common Region ArrayHash TableStringTreeDepth-First SearchBreadth-First SearchBinary LiftingLowest Common Ancestor	Medium	Airbnb	88%	68.3%
#1916	Count Ways to Build Rooms in an Ant Colony ArrayMathDynamic ProgrammingTreeDepth-First SearchGraph TheoryTopological SortCombinatoricsDP on TreesFermat's Little Theorem	Hard	Adobe	88%	51.8%
#3787	Find Diameter Endpoints of a Tree TreeBreadth-First SearchGraph Theory	Medium	Agoda	84%	66.9%
#3820	Pythagorean Distance Nodes in a Tree TreeBreadth-First Search	Medium	PayPal	78%	58.0%
#2920	Maximum Points After Collecting Coins From All Nodes ArrayDynamic ProgrammingBit ManipulationTreeDepth-First SearchMemoizationDP on Trees	Hard	DE Shaw	75%	36.9%
#3383	Minimum Runes to Add to Cast Spell ArrayDepth-First SearchBreadth-First SearchGraph TheoryTopological Sort	Hard	DE Shaw	75%	44.7%
#3575	Maximum Good Subtree Score ArrayDynamic ProgrammingBit ManipulationTreeDepth-First SearchBitmask	Hard	Infosys	75%	45.7%
#2445	Number of Nodes With Value One ArrayTreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Infosys	75%	66.3%
#2867	Count Valid Paths in a Tree MathDynamic ProgrammingTreeDepth-First SearchNumber TheoryPrimality TestSieve TheoryPrime Number Sieve	Hard	Gameskraft	64%	36.6%
#3939	Count Non Adjacent Subsets in a Rooted Tree ArrayDynamic ProgrammingTreeDepth-First Search	Hard	Infosys	63%	56.1%
#3515	Shortest Path in a Weighted Tree ArrayTreeDepth-First SearchBinary Indexed TreeSegment Tree	Hard	Juspay	56%	42.6%
#3313	Find the Last Marked Nodes in Tree TreeDepth-First Search	Hard	Salesforce	55%	56.5%
#3528	Unit Conversion I Depth-First SearchBreadth-First SearchGraph Theory	Medium	Adobe	52%	54.1%
#1719	Number Of Ways To Reconstruct A Tree ArrayHash TableTreeGraph TheorySimulation	Hard	Uber	50%	46.2%
#3481	Apply Substitutions ArrayHash TableStringDepth-First SearchBreadth-First SearchGraph TheoryTopological Sort	Medium	Google	43%	77.9%
#2673	Make Costs of Paths Equal in a Binary Tree ArrayDynamic ProgrammingGreedyTreeBinary Tree	Medium	TikTok	39%	58.8%
#672	Bulb Switcher II MathBit ManipulationDepth-First SearchBreadth-First Search	Medium	Microsoft	38%	50.4%
#3772	Maximum Subgraph Score in a Tree ArrayDynamic ProgrammingTreeDepth-First Search	Hard	Microsoft	29%	71.0%
#1628	Design an Expression Tree With Evaluate Function ArrayMathStackTreeDesignBinary Tree	Medium	Amazon	28%	82.5%
#1273	Delete Tree Nodes ArrayTreeDepth-First SearchBreadth-First SearchDP on Trees	Medium	Microsoft	27%	61.6%
#1469	Find All The Lonely Nodes TreeDepth-First SearchBreadth-First SearchBinary Tree	Easy	Microsoft	27%	84.1%
#3157	Find the Level of Tree with Minimum Sum TreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Microsoft	27%	69.5%
#1379	Find a Corresponding Node of a Binary Tree in a Clone of That Tree TreeDepth-First SearchBreadth-First SearchBinary Tree	Easy	Meta	27%	85.9%
#1586	Binary Search Tree Iterator II StackTreeDesignBinary Search TreeBinary TreeIterator	Medium	Meta	25%	63.5%
#998	Maximum Binary Tree II TreeBinary Tree	Medium	Meta	25%	70.7%
#1973	Count Nodes Equal to Sum of Descendants TreeDepth-First SearchBinary Tree	Medium	Meta	25%	77.3%
#3535	Unit Conversion II ArrayMathDepth-First SearchBreadth-First SearchGraph Theory	Medium	TikTok	25%	65.8%
#1214	Two Sum BSTs Two PointersBinary SearchStackTreeDepth-First SearchBinary Search TreeBinary Tree	Medium	Amazon	25%	68.2%
#1080	Insufficient Nodes in Root to Leaf Paths TreeDepth-First SearchBinary Tree	Medium	Amazon	25%	55.4%
#2973	Find Number of Coins to Place in Tree Nodes Dynamic ProgrammingTreeDepth-First SearchSortingHeap (Priority Queue)DP on Trees	Hard	Amazon	25%	37.7%
#3786	Total Sum of Interaction Cost in Tree Groups ArrayTreeDepth-First Search	Hard	Amazon	25%	54.4%
#663	Equal Tree Partition TreeDepth-First SearchBinary Tree	Medium	Amazon	25%	42.3%
#1120	Maximum Average Subtree TreeDepth-First SearchBinary Tree	Medium	Amazon	25%	67.0%
#1490	Clone N-ary Tree Hash TableTreeDepth-First SearchBreadth-First Search	Medium	Amazon	25%	83.2%
#1597	Build Binary Expression Tree From Infix Expression StringStackTreeBinary Tree	Hard	Amazon	25%	62.9%
#2123	Minimum Operations to Remove Adjacent Ones in Matrix ArrayDepth-First SearchGraph TheoryMatrixEdmonds–Karp AlgorithmMPM AlgorithmPush-Relabel AlgorithmFlow NetworkDinic's Algorithm	Hard	Amazon	25%	43.6%
#753	Cracking the Safe StringDepth-First SearchGraph TheoryEulerian CircuitEulerian PathEulerian Graph	Hard	Google	25%	58.5%
#3327	Check if DFS Strings Are Palindromes ArrayHash TableStringTreeDepth-First SearchHash Function	Hard	Google	25%	20.8%
#331	Verify Preorder Serialization of a Binary Tree StringStackTreeBinary Tree	Medium	Google	25%	47.5%
#2476	Closest Nodes Queries in a Binary Search Tree ArrayBinary SearchTreeDepth-First SearchBinary Search TreeBinary Tree	Medium	Google	25%	44.7%
#2556	Disconnect Path in a Binary Matrix by at Most One Flip ArrayDynamic ProgrammingDepth-First SearchBreadth-First SearchMatrix	Medium	Google	25%	28.0%
#302	Smallest Rectangle Enclosing Black Pixels ArrayBinary SearchDepth-First SearchBreadth-First SearchMatrix	Hard	Google	25%	61.0%
#2331	Evaluate Boolean Binary Tree TreeDepth-First SearchBinary Tree	Easy	Google	25%	82.4%
#685	Redundant Connection II Depth-First SearchBreadth-First SearchUnion-FindGraph Theory	Hard	Google	25%	36.4%
#1516	Move Sub-Tree of N-Ary Tree TreeDepth-First Search	Hard	Google	25%	59.8%
#1602	Find Nearest Right Node in Binary Tree TreeBreadth-First SearchBinary Tree	Medium	Google	25%	75.1%
#1612	Check If Two Expression Trees are Equivalent Hash TableTreeDepth-First SearchBinary TreeCounting	Medium	Google	25%	71.8%
#1660	Correct a Binary Tree Hash TableTreeDepth-First SearchBreadth-First SearchBinary Tree	Medium	Google	25%	74.3%
#1666	Change the Root of a Binary Tree TreeDepth-First SearchBinary Tree	Medium	Google	25%	75.0%
#1766	Tree of Coprimes ArrayMathTreeDepth-First SearchNumber Theory	Hard	Google	25%	44.4%
#1858	Longest Word With All Prefixes ArrayStringDepth-First SearchTrie	Medium	Google	25%	72.1%
#2313	Minimum Flips in Binary Tree to Get Result Dynamic ProgrammingTreeDepth-First SearchBinary Tree	Hard	Google	25%	57.0%
#2689	Extract Kth Character From The Rope Tree TreeDepth-First SearchBinary Tree	Easy	Google	25%	73.3%
#2925	Maximum Score After Applying Operations on a Tree Dynamic ProgrammingTreeDepth-First SearchDP on Trees	Medium	Google	25%	47.5%
#3493	Properties Graph ArrayHash TableDepth-First SearchBreadth-First SearchUnion-FindGraph Theory	Medium	Amazon	13%	49.1%
#3585	Find Weighted Median Node in Tree ArrayBinary SearchDynamic ProgrammingBit ManipulationTreeDepth-First Search	Hard	Google	13%	26.2%
#3319	K-th Largest Perfect Subtree Size in Binary Tree TreeDepth-First SearchSortingBinary Tree	Medium	Google	13%	62.4%
#3486	Longest Special Path II ArrayHash TableTreeDepth-First SearchPrefix Sum	Hard	Google	13%	19.8%
#2277	Closest Node to Path in Tree ArrayTreeDepth-First SearchBreadth-First Search	Hard	Google	13%	62.5%
#499	The Maze III ArrayStringDepth-First SearchBreadth-First SearchGraph TheoryHeap (Priority Queue)MatrixShortest PathDijkstra's AlgorithmHeuristic SearchA* Search	Hard	Google	13%	52.5%

Showing 353 of 353 problems in Tree Depth-First Search (DFS)Filtered: All Companies