What is the Prefix Sum & Hash Map pattern in coding interviews?

O(1) range queries and subarray sum lookups using cumulative totals It is categorized under Fundamentals and features 205 curated interview problems across Easy (17), Medium (131), and Hard (57) difficulties.

Which tech companies frequently test Prefix Sum & Hash Map?

Companies frequently asking Prefix Sum & Hash Map questions include Google, Amazon, Microsoft, Meta, Bloomberg, Uber.

How do I master the Prefix Sum & Hash Map pattern?

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

Prefix Sum & Hash Map

Fundamentals

O(1) range queries and subarray sum lookups using cumulative totals

205 problems·17 Easy·131 Medium·57 Hard

Pattern Study Guide & Cheat Sheet· O(n) single pass · O(n) for hash map / prefix array

▼

Precompute cumulative values so any range sum sum(nums[i..j]) is computed in O(1) time as prefix[j+1] - prefix[i], or combined with a Hash Map to find subarrays in O(N).

Core Invariant: Sum(i..j) = Prefix[j] - Prefix[i-1] = target implies Prefix[i-1] = Prefix[j] - target. By storing seen prefix sums in a Hash Map, we can count or find valid starting indices in O(1)!

Recognize it (Keywords & Signals)

Subarray sum equals K (especially with negative numbers)
Number of continuous subarrays divisible by K
Longest subarray with equal number of 0s and 1s
Repeated range sum queries on static array / 2D matrix

When NOT to use

Frequent updates/modifications to array elements (use Fenwick Tree / Segment Tree for O(log n) dynamic updates).

How to solve (Step-by-step)

1.Initialize `curr_sum = 0`, `count = 0`, and `seen = {0: 1}` (empty prefix has sum 0 occurring once).
2.Iterate through each number `x` in the array.
3.Add to running sum: `curr_sum += x`.
4.Check if `(curr_sum - target)` exists in `seen`. If so, add its frequency to `count`.
5.Record current sum in map: `seen[curr_sum] = seen.get(curr_sum, 0) + 1`.
6.Return `count`.

Watch for (Interview Traps)

Forgetting `{0: 1}` in the hash map (fails on valid subarrays starting from index 0)
Updating the hash map BEFORE checking `curr_sum - k` (can cause self-match when k = 0)
Mistakenly using Sliding Window when numbers can be negative (Sliding Window requires monotonic sums)

Prefix Sum + Hash Map (Subarray Sum Equals K)

def subarray_sum_equals_k(nums: list[int], k: int) -> int:
    prefix_counts = {0: 1}  # Base case: sum 0 occurs once before array starts
    curr_sum = 0
    total_subarrays = 0
    
    for num in nums:
        curr_sum += num
        # If (curr_sum - k) was seen before, those prior points form valid subarrays
        diff = curr_sum - k
        if diff in prefix_counts:
            total_subarrays += prefix_counts[diff]
            
        prefix_counts[curr_sum] = prefix_counts.get(curr_sum, 0) + 1
        
    return total_subarrays

Cost: O(n) single pass · O(n) for hash map / prefix array (Reduces an O(n^2) brute force subarray check down to O(n).)

Canonical problems

#560 Subarray Sum Equals K: Count subarrays with sum K even with negative numbers

#525 Contiguous Array: Map 0 -> -1; longest subarray with sum 0 has equal 0s and 1s

#238 Product of Array Except Self: Combine prefix products from left and suffix products from right

#304 Range Sum Query 2D - Immutable: 2D prefix grid inclusion-exclusion area formula

⌘K

#253Meeting Rooms II

Medium·47 companies·Max freq 100%·Acc 52.7%

SplunkSnapWorldQuant+44

#560Subarray Sum Equals K

Medium·47 companies·Max freq 88%·Acc 47.7%

MetaRippleAMD+44

#238Product of Array Except Self

Medium·44 companies·Max freq 100%·Acc 69.1%

ThousandEyesAsanaQuantcast+41

#528Random Pick with Weight

Medium·26 companies·Max freq 100%·Acc 49.2%

Two SigmaLiftoffNuro+23

#410Split Array Largest Sum

Hard·22 companies·Max freq 100%·Acc 60.9%

BaiduYugabyteZeta Global+19

#713Subarray Product Less Than K

Medium·22 companies·Max freq 100%·Acc 54.7%

YatraSquarepoint CapitalSamsung+19

#1004Max Consecutive Ones III

Medium·22 companies·Max freq 88%·Acc 68.0%

LinkedInRokuMeta+19

#209Minimum Size Subarray Sum

Medium·19 companies·Max freq 88%·Acc 52.2%

BCGCitigroupCitigroup+16

#525Contiguous Array

Medium·16 companies·Max freq 88%·Acc 51.7%

MotiveAkamaiOracle+13

#1838Frequency of the Most Frequent Element

Medium·12 companies·Max freq 100%·Acc 45.0%

Pony.aiPony.aiUrban Company+9

#1094Car Pooling

Medium·12 companies·Max freq 89%·Acc 56.4%

CareemLyftZepto+9

#1352Product of the Last K Numbers

Medium·11 companies·Max freq 100%·Acc 63.0%

StarbucksTargetTekion+8

#1423Maximum Points You Can Obtain from Cards

Medium·11 companies·Max freq 100%·Acc 58.0%

FlipkartPhonePeSprinklr+8

#974Subarray Sums Divisible by K

Medium·11 companies·Max freq 70%·Acc 56.5%

HashedInTikTokJPMorgan Chase+8

#1413Minimum Value to Get Positive Step by Step Sum

Easy·10 companies·Max freq 100%·Acc 64.8%

SwiggyDellYelp+7

#304Range Sum Query 2D - Immutable

Medium·10 companies·Max freq 71%·Acc 58.6%

OktaWaymoUpstart+7

#523Continuous Subarray Sum

Medium·10 companies·Max freq 63%·Acc 31.5%

MetaPhonePeBloomberg+7

#2559Count Vowel Strings in Ranges

Medium·9 companies·Max freq 88%·Acc 67.9%

PayPalTwilioIBM+6

#1248Count Number of Nice Subarrays

Medium·9 companies·Max freq 75%·Acc 75.4%

RobloxDeliverooTikTok+6

#862Shortest Subarray with Sum at Least K

Hard·8 companies·Max freq 100%·Acc 32.9%

DevRevPhonePeGoldman Sachs+5

#303Range Sum Query - Immutable

Easy·8 companies·Max freq 63%·Acc 72.7%

PalantirInfosysMeta+5

#325Maximum Size Subarray Sum Equals k

Medium·8 companies·Max freq 63%·Acc 50.9%

PalantirMetaGoldman Sachs+5

#2021Brightest Position on Street

Medium·7 companies·Max freq 100%·Acc 60.7%

RobinhoodRobloxTikTok+4

#1664Ways to Make a Fair Array

Medium·7 companies·Max freq 100%·Acc 67.3%

DunzoFlatiron HealthPhonePe+4

#1854Maximum Population Year

Easy·7 companies·Max freq 100%·Acc 64.3%

EnvoyMicrosoftApple+4

#2406Divide Intervals Into Minimum Number of Groups

Medium·7 companies·Max freq 88%·Acc 63.6%

AdobeWalmart LabsIBM+4

#1590Make Sum Divisible by P

Medium·7 companies·Max freq 65%·Acc 42.6%

PhonePeSamsungAmazon+4

#1732Find the Highest Altitude

Easy·7 companies·Max freq 50%·Acc 84.7%

CognizantZohoGoogle+4

#930Binary Subarrays With Sum

Medium·7 companies·Max freq 41%·Acc 69.3%

BloombergNvidiaAmazon+4

#1524Number of Sub-arrays With Odd Sum

Medium·6 companies·Max freq 100%·Acc 55.7%

DirectiMicrosoftAmazon+3

#2381Shifting Letters II

Medium·6 companies·Max freq 100%·Acc 53.8%

VeritasZeta GlobalMeta+3

#3445Maximum Difference Between Even and Odd Frequency II

Hard·6 companies·Max freq 100%·Acc 48.6%

Fractal AnalyticsMicrosoftMeta+3

#2483Minimum Penalty for a Shop

Medium·6 companies·Max freq 100%·Acc 71.2%

StripeAmazonBloomberg+3

#2145Count the Hidden Sequences

Medium·6 companies·Max freq 96%·Acc 56.7%

ZomatoTikTokAmazon+3

#2448Minimum Cost to Make Array Equal

Hard·6 companies·Max freq 75%·Acc 46.8%

CiscoHashedInOracle+3

#689Maximum Sum of 3 Non-Overlapping Subarrays

Hard·6 companies·Max freq 63%·Acc 59.9%

General MotorsMetaGoogle+3

#1480Running Sum of 1d Array

Easy·6 companies·Max freq 50%·Acc 87.0%

GoogleAmazonMicrosoft+3

#3191Minimum Operations to Make Binary Array Elements Equal to One I

Medium·6 companies·Max freq 50%·Acc 80.4%

UberMicrosoftGoogle+3

#3494Find the Minimum Amount of Time to Brew Potions

Medium·6 companies·Max freq 50%·Acc 62.7%

Goldman SachsGoogleBloomberg+3

#1930Unique Length-3 Palindromic Subsequences

Medium·6 companies·Max freq 39%·Acc 73.8%

VisaGoogleAmazon+3

#1769Minimum Number of Operations to Move All Balls to Each Box

Medium·6 companies·Max freq 38%·Acc 90.2%

GoogleMetaTikTok+3

#1371Find the Longest Substring Containing Vowels in Even Counts

Medium·6 companies·Max freq 38%·Acc 75.6%

MicrosoftGoldman SachsBloomberg+3

#1140Stone Game II

Medium·6 companies·Max freq 25%·Acc 72.8%

UberAmazonGoogle+3

#3714Longest Balanced Substring II

Medium·6 companies·Max freq 25%·Acc 41.9%

tcsBloombergAmazon+3

#1674Minimum Moves to Make Array Complementary

Medium·5 companies·Max freq 100%·Acc 64.9%

CureFitMicrosoftAmazon+2

#2615Sum of Distances

Medium·5 companies·Max freq 100%·Acc 50.3%

BNY MellonMetaAmazon+2

#2439Minimize Maximum of Array

Medium·5 companies·Max freq 100%·Acc 46.6%

PaytmVisaOracle+2

#3152Special Array II

Medium·5 companies·Max freq 100%·Acc 0.5%

National Payments Corporation of IndiaNational Payments Corporation of IndiaAmazon+2

#3355Zero Array Transformation I

Medium·5 companies·Max freq 100%·Acc 54.6%

ChubbGoogleBloomberg+2

#3026Maximum Good Subarray Sum

Medium·5 companies·Max freq 77%·Acc 22.2%

GrowwCoupangAtlassian+2

#2302Count Subarrays With Score Less Than K

Hard·5 companies·Max freq 77%·Acc 62.2%

PinterestGoogleMicrosoft+2

#2438Range Product Queries of Powers

Medium·5 companies·Max freq 68%·Acc 61.2%

TrilogyGoldman SachsGoogle+2

#3432Count Partitions with Even Sum Difference

Easy·5 companies·Max freq 63%·Acc 85.3%

AccentureAmazonBloomberg+2

#3480Maximize Subarrays After Removing One Conflicting Pair

Hard·5 companies·Max freq 55%·Acc 64.5%

LinkedInAmazonGoogle+2

#1074Number of Submatrices That Sum to Target

Hard·5 companies·Max freq 55%·Acc 74.6%

SnapSnapAmazon+2

#3652Best Time to Buy and Sell Stock using Strategy

Medium·5 companies·Max freq 50%·Acc 59.7%

UberVisaMeta+2

#1109Corporate Flight Bookings

Medium·5 companies·Max freq 50%·Acc 67.9%

Goldman SachsPinterestGoogle+2

#307Range Sum Query - Mutable

Medium·5 companies·Max freq 42%·Acc 0.4%

AdobeBloombergMicrosoft+2

#3356Zero Array Transformation II

Medium·5 companies·Max freq 39%·Acc 43.6%

GoogleUberBloomberg+2

#3362Zero Array Transformation III

Medium·5 companies·Max freq 28%·Acc 54.7%

GoogleBloombergMeta+2

#3737Count Subarrays With Majority Element I

Medium·5 companies·Max freq 25%·Acc 75.7%

MicrosoftAmazonMeta+2

#3333Find the Original Typed String II

Hard·5 companies·Max freq 18%·Acc 45.5%

GoogleMicrosoftAmazon+2

#3699Number of ZigZag Arrays I

Hard·5 companies·Max freq 18%·Acc 50.5%

AmazonGoogleMeta+2

#3354Make Array Elements Equal to Zero

Easy·5 companies·Max freq 13%·Acc 68.3%

BloombergMetaAmazon+2

#1292Maximum Side Length of a Square with Sum Less than or Equal to Threshold

Medium·4 companies·Max freq 100%·Acc 65.4%

IMCFractal AnalyticsGoogle+1

#2024Maximize the Confusion of an Exam

Medium·4 companies·Max freq 100%·Acc 70.2%

ArcesiumMetaAmazon+1

#3225Maximum Score From Grid Operations

Hard·4 companies·Max freq 100%·Acc 0.6%

Hudson River TradingHudson River TradingGoogle+1

#1878Get Biggest Three Rhombus Sums in a Grid

Medium·4 companies·Max freq 100%·Acc 71.3%

QuoraUberAmazon+1

#1991Find the Middle Index in Array

Easy·4 companies·Max freq 100%·Acc 70.1%

Code StudioBloombergAmazon+1

#2528Maximize the Minimum Powered City

Hard·4 companies·Max freq 100%·Acc 61.5%

TeradataAmazonGoogle+1

#3636Threshold Majority Queries

Hard·4 companies·Max freq 78%·Acc 22.4%

AdobeMetaAmazon+1

#1703Minimum Adjacent Swaps for K Consecutive Ones

Hard·4 companies·Max freq 67%·Acc 42.4%

TuringMicrosoftGoogle+1

#1314Matrix Block Sum

Medium·4 companies·Max freq 56%·Acc 76.7%

VisaGoogleMeta+1

#3719Longest Balanced Subarray I

Medium·4 companies·Max freq 51%·Acc 65.7%

IntuitBloombergAmazon+1

#1000Minimum Cost to Merge Stones

Hard·4 companies·Max freq 50%·Acc 46.4%

DE ShawAmazonGoogle+1

#3434Maximum Frequency After Subarray Operation

Medium·4 companies·Max freq 50%·Acc 31.4%

AmazonBloombergMicrosoft+1

#1856Maximum Subarray Min-Product

Medium·4 companies·Max freq 50%·Acc 40.6%

UberInfosysAmazon+1

#1685Sum of Absolute Differences in a Sorted Array

Medium·4 companies·Max freq 42%·Acc 68.4%

IBMAmazonMeta+1

#3346Maximum Frequency of an Element After Performing Operations I

Medium·4 companies·Max freq 29%·Acc 40.2%

GoogleMetaAmazon+1

#3381Maximum Subarray Sum With Length Divisible by K

Medium·4 companies·Max freq 25%·Acc 49.7%

BloombergAmazonGoogle+1

#1871Jump Game VII

Medium·4 companies·Max freq 25%·Acc 35.6%

GoogleAmazonBloomberg+1

#2574Left and Right Sum Differences

Easy·4 companies·Max freq 25%·Acc 89.6%

GoogleBloombergMeta+1

#2389Longest Subsequence With Limited Sum

Easy·4 companies·Max freq 25%·Acc 73.7%

UberMetaAmazon+1

#2017Grid Game

Medium·4 companies·Max freq 25%·Acc 60.9%

MicrosoftAmazonBloomberg+1

#3129Find All Possible Stable Binary Arrays I

Medium·4 companies·Max freq 15%·Acc 53.6%

GoogleMetaAmazon+1

#3578Count Partitions With Max-Min Difference at Most K

Medium·4 companies·Max freq 13%·Acc 58.5%

MetaAmazonMicrosoft+1

#2845Count of Interesting Subarrays

Medium·4 companies·Max freq 13%·Acc 58.0%

MetaBloombergMicrosoft+1

#2906Construct Product Matrix

Medium·4 companies·Max freq 13%·Acc 51.7%

AmazonBloombergMicrosoft+1

#3546Equal Sum Grid Partition I

Medium·4 companies·Max freq 13%·Acc 52.9%

AmazonBloombergMicrosoft+1

#1712Ways to Split Array Into Three Subarrays

Medium·3 companies·Max freq 100%·Acc 34.4%

RobinhoodTekionGoogle

#1889Minimum Space Wasted From Packaging

Hard·3 companies·Max freq 100%·Acc 33.7%

IMCTwo SigmaAmazon

#2968Apply Operations to Maximize Frequency Score

Hard·3 companies·Max freq 100%·Acc 39.4%

Deutsche BankPhonePeGoogle

#1895Largest Magic Square

Medium·3 companies·Max freq 100%·Acc 75.2%

WayfairAmazonGoogle

#1310XOR Queries of a Subarray

Medium·3 companies·Max freq 100%·Acc 78.0%

AirtelGoogleAmazon

#2772Apply Operations to Make All Array Elements Equal to Zero

Medium·3 companies·Max freq 97%·Acc 0.3%

Hudson River TradingAmazonGoogle

#2271Maximum White Tiles Covered by a Carpet

Medium·3 companies·Max freq 92%·Acc 36.1%

LTIMindtreeGoogleAmazon

#1893Check if All the Integers in a Range Are Covered

Easy·3 companies·Max freq 88%·Acc 51.2%

SquarespaceBloombergAmazon

#2055Plates Between Candles

Medium·3 companies·Max freq 88%·Acc 47.6%

AdobeAmazonOracle

#1943Describe the Painting

Medium·3 companies·Max freq 88%·Acc 52.7%

spinnyGoogleAmazon

#3028Ant on the Boundary

Easy·3 companies·Max freq 75%·Acc 74.6%

AccentureGoogleAmazon

#1124Longest Well-Performing Interval

Medium·3 companies·Max freq 75%·Acc 37.9%

InfosysNetAppGoogle

#2222Number of Ways to Select Buildings

Medium·3 companies·Max freq 67%·Acc 51.0%

Dream11DE ShawAmazon

#2488Count Subarrays With Median K

Hard·3 companies·Max freq 52%·Acc 49.0%

SalesforceAmazonGoogle

#1588Sum of All Odd Length Subarrays

Easy·3 companies·Max freq 50%·Acc 84.1%

LinkedInAmazonGoogle

#2536Increment Submatrices by One

Medium·3 companies·Max freq 42%·Acc 73.8%

AdobeGoogleMeta

#1422Maximum Score After Splitting a String

Easy·3 companies·Max freq 30%·Acc 65.1%

GoogleMetaAmazon

#731My Calendar II

Medium·3 companies·Max freq 30%·Acc 63.3%

AppleGoogleAmazon

#2485Find the Pivot Integer

Easy·3 companies·Max freq 25%·Acc 83.8%

AmazonMetaGoogle

#308Range Sum Query 2D - Mutable

Medium·3 companies·Max freq 25%·Acc 45.5%

BloombergGoogleAmazon

#3347Maximum Frequency of an Element After Performing Operations II

Hard·3 companies·Max freq 25%·Acc 53.9%

GoogleAmazonBloomberg

#363Max Sum of Rectangle No Larger Than K

Hard·3 companies·Max freq 25%·Acc 45.7%

GoogleBloombergAmazon

#848Shifting Letters

Medium·3 companies·Max freq 25%·Acc 46.3%

MicrosoftBloombergGoogle

#995Minimum Number of K Consecutive Bit Flips

Hard·3 companies·Max freq 16%·Acc 0.6%

GoogleAmazonMeta

#3756Concatenate Non-Zero Digits and Multiply by Sum II

Medium·3 companies·Max freq 16%·Acc 42.9%

GoogleAmazonBloomberg

#3312Sorted GCD Pair Queries

Hard·3 companies·Max freq 16%·Acc 0.6%

GoogleAmazonBloomberg

#1420Build Array Where You Can Find The Maximum Exactly K Comparisons

Hard·2 companies·Max freq 100%·Acc 65.5%

DunzoGoogle

#2121Intervals Between Identical Elements

Medium·2 companies·Max freq 100%·Acc 48.1%

TuSimpleWayve

#3709Design Exam Scores Tracker

Medium·2 companies·Max freq 92%·Acc 0.4%

MeeshoAmazon

#2552Count Increasing Quadruplets

Hard·2 companies·Max freq 92%·Acc 34.5%

SAPDeutsche Bank

#2955Number of Same-End Substrings

Medium·2 companies·Max freq 90%·Acc 61.7%

SprinklrGoogle

#3070Count Submatrices with Top-Left Element and Sum Less Than k

Medium·2 companies·Max freq 88%·Acc 74.9%

BarclaysGoogle

#3077Maximum Strength of K Disjoint Subarrays

Hard·2 companies·Max freq 75%·Acc 28.1%

DE ShawAmazon

#3410Maximize Subarray Sum After Removing All Occurrences of One Element

Hard·2 companies·Max freq 75%·Acc 23.4%

RubrikGoogle

#1589Maximum Sum Obtained of Any Permutation

Medium·2 companies·Max freq 75%·Acc 41.2%

PayPalGoogle

#2398Maximum Number of Robots Within Budget

Hard·2 companies·Max freq 67%·Acc 38.8%

InMobiAmazon

#3900Longest Balanced Substring After One Swap

Medium·2 companies·Max freq 64%·Acc 0.1%

TekionGoogle

#3653XOR After Range Multiplication Queries I

Medium·2 companies·Max freq 63%·Acc 73.3%

InfosysAmazon

#3655XOR After Range Multiplication Queries II

Hard·2 companies·Max freq 63%·Acc 47.7%

InfosysAmazon

#1829Maximum XOR for Each Query

Medium·2 companies·Max freq 50%·Acc 84.7%

UberBloomberg

#3413Maximum Coins From K Consecutive Bags

Medium·2 companies·Max freq 47%·Acc 25.7%

AmazonGoogle

#3130Find All Possible Stable Binary Arrays II

Hard·2 companies·Max freq 42%·Acc 58.8%

IBMAmazon

#2237Count Positions on Street With Required Brightness

Medium·2 companies·Max freq 35%·Acc 0.6%

Capital OneGoogle

#497Random Point in Non-overlapping Rectangles

Medium·2 companies·Max freq 28%·Acc 40.1%

UberGoogle

#2025Maximum Number of Ways to Partition an Array

Hard·2 companies·Max freq 28%·Acc 35.9%

SalesforceGoogle

#3728Stable Subarrays With Equal Boundary and Interior Sum

Medium·2 companies·Max freq 27%·Acc 26.5%

MicrosoftAmazon

#3212Count Submatrices With Equal Frequency of X and Y

Medium·2 companies·Max freq 27%·Acc 69.7%

MicrosoftAmazon

#2391Minimum Amount of Time to Collect Garbage

Medium·2 companies·Max freq 27%·Acc 85.1%

MicrosoftGoogle

#3862Find the Smallest Balanced Index

Medium·2 companies·Max freq 25%·Acc 19.5%

MetaGoogle

#2256Minimum Average Difference

Medium·2 companies·Max freq 25%·Acc 44.0%

AmazonMeta

#2100Find Good Days to Rob the Bank

Medium·2 companies·Max freq 25%·Acc 51.9%

AmazonGoogle

#1525Number of Good Ways to Split a String

Medium·2 companies·Max freq 25%·Acc 68.5%

GoogleAmazon

#813Largest Sum of Averages

Medium·2 companies·Max freq 25%·Acc 55.2%

GoogleAmazon

#3721Longest Balanced Subarray II

Hard·2 companies·Max freq 25%·Acc 33.8%

GoogleAmazon

#370Range Addition

Medium·2 companies·Max freq 25%·Acc 73.1%

GoogleAmazon

#1915Number of Wonderful Substrings

Medium·2 companies·Max freq 25%·Acc 66.6%

UberGoogle

#1442Count Triplets That Can Form Two Arrays of Equal XOR

Medium·2 companies·Max freq 13%·Acc 84.8%

MetaGoogle

#3427Sum of Variable Length Subarrays

Easy·2 companies·Max freq 13%·Acc 85.8%

AmazonGoogle

#3739Count Subarrays With Majority Element II

Hard·2 companies·Max freq 13%·Acc 64.9%

AmazonMicrosoft

#3548Equal Sum Grid Partition II

Hard·2 companies·Max freq 13%·Acc 39.4%

MicrosoftGoogle

#2428Maximum Sum of an Hourglass

Medium·1 companies·Max freq 100%·Acc 76.4%

Nutanix

#1687Delivering Boxes from Storage to Ports

Hard·1 companies·Max freq 100%·Acc 39.9%

Nutanix

#3883Count Non Decreasing Arrays With Given Digit Sums

Hard·1 companies·Max freq 100%·Acc 41.6%

Docusign

#1177Can Make Palindrome from Substring

Medium·1 companies·Max freq 100%·Acc 41.8%

Akuna Capital

#548Split Array with Equal Sum

Hard·1 companies·Max freq 100%·Acc 50.1%

Alibaba

#2505Bitwise OR of All Subsequence Sums

Medium·1 companies·Max freq 100%·Acc 64.1%

Zomato

#2971Find Polygon With the Largest Perimeter

Medium·1 companies·Max freq 100%·Acc 65.6%

Airtel

#2838Maximum Coins Heroes Can Collect

Medium·1 companies·Max freq 100%·Acc 68.8%

Deutsche Bank

#1977Number of Ways to Separate Numbers

Hard·1 companies·Max freq 88%·Acc 21.8%

Walmart Labs

#3179Find the N-th Value After K Seconds

Medium·1 companies·Max freq 88%·Acc 54.1%

Walmart Labs

#3628Maximum Number of Subsequences After One Inserting

Medium·1 companies·Max freq 83%·Acc 32.1%

DE Shaw

#2875Minimum Size Subarray in Infinite Array

Medium·1 companies·Max freq 77%·Acc 32.4%

DE Shaw

#2171Removing Minimum Number of Magic Beans

Medium·1 companies·Max freq 75%·Acc 44.8%

DE Shaw

#2234Maximum Total Beauty of the Gardens

Hard·1 companies·Max freq 75%·Acc 30.2%

Intuit

#2489Number of Substrings With Fixed Ratio

Medium·1 companies·Max freq 75%·Acc 57.2%

Intuit

#1872Stone Game VIII

Hard·1 companies·Max freq 75%·Acc 54.2%

Infosys

#3096Minimum Levels to Gain More Points

Medium·1 companies·Max freq 65%·Acc 40.5%

IBM

#3251Find the Count of Monotonic Pairs II

Hard·1 companies·Max freq 64%·Acc 24.9%

BNY Mellon

#3511Make a Positive Array

Medium·1 companies·Max freq 63%·Acc 36.4%

UKG

#2132Stamping the Grid

Hard·1 companies·Max freq 63%·Acc 35.6%

Rubrik

#3015Count the Number of Houses at a Certain Distance I

Medium·1 companies·Max freq 63%·Acc 58.1%

Oracle

#3017Count the Number of Houses at a Certain Distance II

Hard·1 companies·Max freq 63%·Acc 23.8%

Oracle

#2640Find the Score of All Prefixes of an Array

Medium·1 companies·Max freq 63%·Acc 73.0%

TikTok

#3086Minimum Moves to Pick K Ones

Hard·1 companies·Max freq 63%·Acc 21.8%

TikTok

#3540Minimum Time to Visit All Houses

Medium·1 companies·Max freq 63%·Acc 69.2%

Salesforce

#3891Minimum Increase to Maximize Special Indices

Medium·1 companies·Max freq 50%·Acc 19.8%

#2420Find All Good Indices

Medium·1 companies·Max freq 50%·Acc 41.1%

Goldman Sachs

#2848Points That Intersect With Cars

Easy·1 companies·Max freq 50%·Acc 73.5%

Uber

#2281Sum of Total Strength of Wizards

Hard·1 companies·Max freq 40%·Acc 29.6%

Amazon

#1983Widest Pair of Indices With Equal Range Sum

Medium·1 companies·Max freq 27%·Acc 54.1%

Microsoft

#2015Average Height of Buildings in Each Segment

Medium·1 companies·Max freq 27%·Acc 58.7%

Microsoft

#2207Maximize Number of Subsequences in a String

Medium·1 companies·Max freq 25%·Acc 36.2%

Amazon

#2947Count Beautiful Substrings I

Medium·1 companies·Max freq 25%·Acc 61.5%

Amazon

#1621Number of Sets of K Non-Overlapping Line Segments

Medium·1 companies·Max freq 25%·Acc 46.1%

Amazon

#1788Maximize the Beauty of the Garden

Hard·1 companies·Max freq 25%·Acc 65.0%

Amazon

#2219Maximum Sum Score of Array

Medium·1 companies·Max freq 25%·Acc 62.8%

Amazon

#2949Count Beautiful Substrings II

Hard·1 companies·Max freq 25%·Acc 27.8%

Amazon

#3864Minimum Cost to Partition a Binary String

Hard·1 companies·Max freq 25%·Acc 52.6%

Amazon

#1444Number of Ways of Cutting a Pizza

Hard·1 companies·Max freq 25%·Acc 61.6%

Google

#732My Calendar III

Hard·1 companies·Max freq 25%·Acc 72.0%

Google

#2218Maximum Value of K Coins From Piles

Hard·1 companies·Max freq 25%·Acc 60.5%

Google

#1738Find Kth Largest XOR Coordinate Value

Medium·1 companies·Max freq 25%·Acc 64.4%

Google

#2478Number of Beautiful Partitions

Hard·1 companies·Max freq 25%·Acc 33.2%

Google

#644Maximum Average Subarray II

Hard·1 companies·Max freq 25%·Acc 37.8%

Google

#1546Maximum Number of Non-Overlapping Subarrays With Sum Equals Target

Medium·1 companies·Max freq 25%·Acc 49.1%

Google

#1737Change Minimum Characters to Satisfy One of Three Conditions

Medium·1 companies·Max freq 25%·Acc 38.2%

Google

#1906Minimum Absolute Difference Queries

Medium·1 companies·Max freq 25%·Acc 45.9%

Google

#2209Minimum White Tiles After Covering With Carpets

Hard·1 companies·Max freq 25%·Acc 39.1%

Google

#3698Split Array With Minimum Difference

Medium·1 companies·Max freq 18%·Acc 33.6%

Google

#3797Count Routes to Climb a Rectangular Grid

Hard·1 companies·Max freq 13%·Acc 25.1%

Microsoft

#3969Valid Subarrays With Matching Sum Digits I

Medium·1 companies·Max freq 13%·Acc 46.7%

Microsoft

#3486Longest Special Path II

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

Google

#798Smallest Rotation with Highest Score

Hard·1 companies·Max freq 13%·Acc 54.3%

Google

#3538Merge Operations for Minimum Travel Time

Hard·1 companies·Max freq 13%·Acc 31.4%

Google

#3361Shift Distance Between Two Strings

Medium·1 companies·Max freq 13%·Acc 53.8%

Google

#3599Partition Array to Minimize XOR

Medium·1 companies·Max freq 13%·Acc 41.6%

Google

#	Problem	Difficulty	Top Companies↓	Frequency	Acceptance
#253	Meeting Rooms II ArrayTwo PointersGreedySortingHeap (Priority Queue)Prefix Sum	Medium	Splunk Snap WorldQuant Snap+43	100%	52.7%
#560	Subarray Sum Equals K ArrayHash TablePrefix Sum	Medium	Meta Ripple AMD KPMG+43	88%	47.7%
#238	Product of Array Except Self ArrayPrefix Sum	Medium	ThousandEyes Asana Quantcast NeetCode 150+40	100%	69.1%
#528	Random Pick with Weight ArrayMathBinary SearchPrefix SumRandomized	Medium	Two Sigma Liftoff Nuro Meta+22	100%	49.2%
#410	Split Array Largest Sum ArrayBinary SearchDynamic ProgrammingGreedyPrefix Sum	Hard	Baidu Yugabyte Zeta Global Tekion+18	100%	60.9%
#713	Subarray Product Less Than K ArrayBinary SearchSliding WindowPrefix Sum	Medium	Yatra Squarepoint Capital Samsung Revolut+18	100%	54.7%
#1004	Max Consecutive Ones III ArrayBinary SearchSliding WindowPrefix Sum	Medium	LinkedIn Roku Meta Motive+18	88%	68.0%
#209	Minimum Size Subarray Sum ArrayBinary SearchSliding WindowPrefix Sum	Medium	BCG Citigroup Citigroup HCL+15	88%	52.2%
#525	Contiguous Array ArrayHash TablePrefix Sum	Medium	Motive Akamai Oracle Walmart Labs+12	88%	51.7%
#1838	Frequency of the Most Frequent Element ArrayBinary SearchGreedySliding WindowSortingPrefix Sum	Medium	Pony.ai Pony.ai Urban Company Infosys+8	100%	45.0%
#1094	Car Pooling ArraySortingHeap (Priority Queue)SimulationPrefix Sum	Medium	Careem Lyft Zepto Paytm+8	89%	56.4%
#1352	Product of the Last K Numbers ArrayMathDesignData StreamPrefix Sum	Medium	Starbucks Target Tekion ByteDance+7	100%	63.0%
#1423	Maximum Points You Can Obtain from Cards ArraySliding WindowPrefix Sum	Medium	Flipkart PhonePe Sprinklr Expedia+7	100%	58.0%
#974	Subarray Sums Divisible by K	Medium	HashedIn TikTok JPMorgan Chase Uber+7	70%	56.5%
#1413	Minimum Value to Get Positive Step by Step Sum ArrayPrefix Sum	Easy	Swiggy Dell Yelp Expedia+6	100%	64.8%
#304	Range Sum Query 2D - Immutable ArrayDesignMatrixPrefix Sum	Medium	Okta Waymo Upstart Google+6	71%	58.6%
#523	Continuous Subarray Sum ArrayHash TableMathPrefix SumPigeonhole Principle	Medium	Meta PhonePe Bloomberg Yandex+6	63%	31.5%
#2559	Count Vowel Strings in Ranges ArrayStringPrefix Sum	Medium	PayPal Twilio IBM MathWorks+5	88%	67.9%
#1248	Count Number of Nice Subarrays ArrayHash TableMathSliding WindowPrefix Sum	Medium	Roblox Deliveroo TikTok Microsoft+5	75%	75.4%
#862	Shortest Subarray with Sum at Least K ArrayBinary SearchQueueSliding WindowHeap (Priority Queue)Prefix SumMonotonic Queue	Hard	DevRev PhonePe Goldman Sachs Amazon+4	100%	32.9%
#303	Range Sum Query - Immutable ArrayDesignPrefix Sum	Easy	Palantir Infosys Meta tcs+4	63%	72.7%
#325	Maximum Size Subarray Sum Equals k ArrayHash TablePrefix Sum	Medium	Palantir Meta Goldman Sachs Oracle+4	63%	50.9%
#2021	Brightest Position on Street ArraySortingPrefix SumOrdered Set	Medium	Robinhood Roblox TikTok Capital One+3	100%	60.7%
#1664	Ways to Make a Fair Array ArrayPrefix Sum	Medium	Dunzo Flatiron Health PhonePe Twilio+3	100%	67.3%
#1854	Maximum Population Year ArrayCountingPrefix Sum	Easy	Envoy Microsoft Apple Bloomberg+3	100%	64.3%
#2406	Divide Intervals Into Minimum Number of Groups ArrayTwo PointersGreedySortingHeap (Priority Queue)Prefix Sum	Medium	Adobe Walmart Labs IBM Meta+3	88%	63.6%
#1590	Make Sum Divisible by P ArrayHash TablePrefix Sum	Medium	PhonePe Samsung Amazon Google+3	65%	42.6%
#1732	Find the Highest Altitude ArrayPrefix Sum	Easy	Cognizant Zoho Google Amazon+3	50%	84.7%
#930	Binary Subarrays With Sum ArrayHash TableSliding WindowPrefix Sum	Medium	Bloomberg Nvidia Amazon Google+3	41%	69.3%
#1524	Number of Sub-arrays With Odd Sum ArrayMathDynamic ProgrammingPrefix Sum	Medium	Directi Microsoft Amazon Google+2	100%	55.7%
#2381	Shifting Letters II ArrayStringPrefix Sum	Medium	Veritas Zeta Global Meta Google+2	100%	53.8%
#3445	Maximum Difference Between Even and Odd Frequency II StringSliding WindowEnumerationPrefix Sum	Hard	Fractal Analytics Microsoft Meta Amazon+2	100%	48.6%
#2483	Minimum Penalty for a Shop StringPrefix Sum	Medium	Stripe Amazon Bloomberg Meta+2	100%	71.2%
#2145	Count the Hidden Sequences ArrayPrefix Sum	Medium	Zomato TikTok Amazon Meta+2	96%	56.7%
#2448	Minimum Cost to Make Array Equal ArrayBinary SearchGreedySortingPrefix Sum	Hard	Cisco HashedIn Oracle Amazon+2	75%	46.8%
#689	Maximum Sum of 3 Non-Overlapping Subarrays ArrayDynamic ProgrammingSliding WindowPrefix Sum	Hard	General Motors Meta Google Microsoft+2	63%	59.9%
#1480	Running Sum of 1d Array ArrayPrefix Sum	Easy	Google Amazon Microsoft tcs+2	50%	87.0%
#3191	Minimum Operations to Make Binary Array Elements Equal to One I ArrayBit ManipulationQueueSliding WindowPrefix Sum	Medium	Uber Microsoft Google Amazon+2	50%	80.4%
#3494	Find the Minimum Amount of Time to Brew Potions ArraySimulationPrefix Sum	Medium	Goldman Sachs Google Bloomberg Meta+2	50%	62.7%
#1930	Unique Length-3 Palindromic Subsequences Hash TableStringBit ManipulationPrefix Sum	Medium	Visa Google Amazon Bloomberg+2	39%	73.8%
#1769	Minimum Number of Operations to Move All Balls to Each Box ArrayStringPrefix Sum	Medium	Google Meta TikTok Bloomberg+2	38%	90.2%
#1371	Find the Longest Substring Containing Vowels in Even Counts Hash TableStringBit ManipulationPrefix Sum	Medium	Microsoft Goldman Sachs Bloomberg Meta+2	38%	75.6%
#1140	Stone Game II ArrayMathDynamic ProgrammingMinimaxPrefix SumGame TheoryZero-Sum Game	Medium	Uber Amazon Google Meta+2	25%	72.8%
#3714	Longest Balanced Substring II Hash TableStringPrefix Sum	Medium	tcs Bloomberg Amazon Meta+2	25%	41.9%
#1674	Minimum Moves to Make Array Complementary ArrayHash TablePrefix Sum	Medium	CureFit Microsoft Amazon Meta+1	100%	64.9%
#2615	Sum of Distances ArrayHash TablePrefix Sum	Medium	BNY Mellon Meta Amazon Microsoft+1	100%	50.3%
#2439	Minimize Maximum of Array ArrayBinary SearchDynamic ProgrammingGreedyPrefix Sum	Medium	Paytm Visa Oracle Microsoft+1	100%	46.6%
#3152	Special Array II ArrayBinary SearchPrefix Sum	Medium	National Payments Corporation of India National Payments Corporation of India Amazon Bloomberg+1	100%	0.5%
#3355	Zero Array Transformation I ArrayPrefix Sum	Medium	Chubb Google Bloomberg Amazon+1	100%	54.6%
#3026	Maximum Good Subarray Sum ArrayHash TablePrefix Sum	Medium	Groww Coupang Atlassian Google+1	77%	22.2%
#2302	Count Subarrays With Score Less Than K ArrayBinary SearchSliding WindowPrefix Sum	Hard	Pinterest Google Microsoft Meta+1	77%	62.2%
#2438	Range Product Queries of Powers ArrayBit ManipulationPrefix Sum	Medium	Trilogy Goldman Sachs Google Amazon+1	68%	61.2%
#3432	Count Partitions with Even Sum Difference ArrayMathPrefix Sum	Easy	Accenture Amazon Bloomberg Microsoft+1	63%	85.3%
#3480	Maximize Subarrays After Removing One Conflicting Pair ArraySegment TreeEnumerationPrefix Sum	Hard	LinkedIn Amazon Google Bloomberg+1	55%	64.5%
#1074	Number of Submatrices That Sum to Target ArrayHash TableMatrixPrefix Sum	Hard	Snap Snap Amazon Google+1	55%	74.6%
#3652	Best Time to Buy and Sell Stock using Strategy ArraySliding WindowPrefix Sum	Medium	Uber Visa Meta Amazon+1	50%	59.7%
#1109	Corporate Flight Bookings ArrayPrefix Sum	Medium	Goldman Sachs Pinterest Google Meta+1	50%	67.9%
#307	Range Sum Query - Mutable ArrayDivide and ConquerDesignBinary Indexed TreeSegment TreeSqrt Decomposition	Medium	Adobe Bloomberg Microsoft Google+1	42%	0.4%
#3356	Zero Array Transformation II ArrayTwo PointersBinary SearchPrefix Sum	Medium	Google Uber Bloomberg Meta+1	39%	43.6%
#3362	Zero Array Transformation III ArrayTwo PointersGreedySortingHeap (Priority Queue)Prefix Sum	Medium	Google Bloomberg Meta Amazon+1	28%	54.7%
#3737	Count Subarrays With Majority Element I ArrayHash TableDivide and ConquerSegment TreeMerge SortCountingPrefix Sum	Medium	Microsoft Amazon Meta Bloomberg+1	25%	75.7%
#3333	Find the Original Typed String II StringDynamic ProgrammingPrefix Sum	Hard	Google Microsoft Amazon Meta+1	18%	45.5%
#3699	Number of ZigZag Arrays I Dynamic ProgrammingPrefix Sum	Hard	Amazon Google Meta Bloomberg+1	18%	50.5%
#3354	Make Array Elements Equal to Zero ArraySimulationPrefix Sum	Easy	Bloomberg Meta Amazon Microsoft+1	13%	68.3%
#1292	Maximum Side Length of a Square with Sum Less than or Equal to Threshold ArrayBinary SearchMatrixPrefix Sum	Medium	IMC Fractal Analytics Google Amazon	100%	65.4%
#2024	Maximize the Confusion of an Exam StringBinary SearchSliding WindowPrefix Sum	Medium	Arcesium Meta Amazon Google	100%	70.2%
#3225	Maximum Score From Grid Operations ArrayDynamic ProgrammingMatrixPrefix Sum	Hard	Hudson River Trading Hudson River Trading Google Amazon	100%	0.6%
#1878	Get Biggest Three Rhombus Sums in a Grid ArrayMathSortingHeap (Priority Queue)MatrixPrefix Sum	Medium	Quora Uber Amazon Google	100%	71.3%
#1991	Find the Middle Index in Array ArrayPrefix Sum	Easy	Code Studio Bloomberg Amazon Google	100%	70.1%
#2528	Maximize the Minimum Powered City ArrayBinary SearchGreedyQueueSliding WindowPrefix Sum	Hard	Teradata Amazon Google Bloomberg	100%	61.5%
#3636	Threshold Majority Queries ArrayHash TableBinary SearchDivide and ConquerCountingPrefix Sum	Hard	Adobe Meta Amazon Google	78%	22.4%
#1703	Minimum Adjacent Swaps for K Consecutive Ones ArrayGreedySliding WindowPrefix Sum	Hard	Turing Microsoft Google Amazon	67%	42.4%
#1314	Matrix Block Sum ArrayMatrixPrefix Sum	Medium	Visa Google Meta Amazon	56%	76.7%
#3719	Longest Balanced Subarray I ArrayHash TableDivide and ConquerSegment TreePrefix Sum	Medium	Intuit Bloomberg Amazon Google	51%	65.7%
#1000	Minimum Cost to Merge Stones ArrayDynamic ProgrammingPrefix Sum	Hard	DE Shaw Amazon Google Microsoft	50%	46.4%
#3434	Maximum Frequency After Subarray Operation ArrayHash TableDynamic ProgrammingGreedyEnumerationPrefix Sum	Medium	Amazon Bloomberg Microsoft Google	50%	31.4%
#1856	Maximum Subarray Min-Product ArrayStackMonotonic StackPrefix SumCartesian Tree	Medium	Uber Infosys Amazon Google	50%	40.6%
#1685	Sum of Absolute Differences in a Sorted Array ArrayMathPrefix Sum	Medium	IBM Amazon Meta Google	42%	68.4%
#3346	Maximum Frequency of an Element After Performing Operations I ArrayBinary SearchSliding WindowSortingPrefix Sum	Medium	Google Meta Amazon Bloomberg	29%	40.2%
#3381	Maximum Subarray Sum With Length Divisible by K ArrayHash TablePrefix Sum	Medium	Bloomberg Amazon Google Meta	25%	49.7%
#1871	Jump Game VII StringDynamic ProgrammingSliding WindowPrefix Sum	Medium	Google Amazon Bloomberg Meta	25%	35.6%
#2574	Left and Right Sum Differences ArrayPrefix Sum	Easy	Google Bloomberg Meta Amazon	25%	89.6%
#2389	Longest Subsequence With Limited Sum ArrayBinary SearchGreedySortingPrefix Sum	Easy	Uber Meta Amazon Google	25%	73.7%
#2017	Grid Game ArrayMatrixPrefix Sum	Medium	Microsoft Amazon Bloomberg Google	25%	60.9%
#3129	Find All Possible Stable Binary Arrays I Dynamic ProgrammingPrefix Sum	Medium	Google Meta Amazon Microsoft	15%	53.6%
#3578	Count Partitions With Max-Min Difference at Most K ArrayDynamic ProgrammingQueueSliding WindowPrefix SumMonotonic Queue	Medium	Meta Amazon Microsoft Google	13%	58.5%
#2845	Count of Interesting Subarrays ArrayHash TablePrefix Sum	Medium	Meta Bloomberg Microsoft Google	13%	58.0%
#2906	Construct Product Matrix ArrayMatrixPrefix Sum	Medium	Amazon Bloomberg Microsoft Google	13%	51.7%
#3546	Equal Sum Grid Partition I ArrayMatrixEnumerationPrefix Sum	Medium	Amazon Bloomberg Microsoft Google	13%	52.9%
#1712	Ways to Split Array Into Three Subarrays ArrayTwo PointersBinary SearchPrefix Sum	Medium	Robinhood Tekion Google	100%	34.4%
#1889	Minimum Space Wasted From Packaging ArrayBinary SearchSortingPrefix Sum	Hard	IMC Two Sigma Amazon	100%	33.7%
#2968	Apply Operations to Maximize Frequency Score ArrayBinary SearchSliding WindowSortingPrefix Sum	Hard	Deutsche Bank PhonePe Google	100%	39.4%
#1895	Largest Magic Square ArrayMatrixPrefix Sum	Medium	Wayfair Amazon Google	100%	75.2%
#1310	XOR Queries of a Subarray ArrayBit ManipulationPrefix Sum	Medium	Airtel Google Amazon	100%	78.0%
#2772	Apply Operations to Make All Array Elements Equal to Zero ArrayPrefix Sum	Medium	Hudson River Trading Amazon Google	97%	0.3%
#2271	Maximum White Tiles Covered by a Carpet ArrayBinary SearchGreedySliding WindowSortingPrefix Sum	Medium	LTIMindtree Google Amazon	92%	36.1%
#1893	Check if All the Integers in a Range Are Covered ArrayHash TablePrefix Sum	Easy	Squarespace Bloomberg Amazon	88%	51.2%
#2055	Plates Between Candles ArrayStringBinary SearchPrefix Sum	Medium	Adobe Amazon Oracle	88%	47.6%
#1943	Describe the Painting ArrayHash TableSortingPrefix Sum	Medium	spinny Google Amazon	88%	52.7%
#3028	Ant on the Boundary ArraySimulationPrefix Sum	Easy	Accenture Google Amazon	75%	74.6%
#1124	Longest Well-Performing Interval ArrayHash TableStackMonotonic StackPrefix Sum	Medium	Infosys NetApp Google	75%	37.9%
#2222	Number of Ways to Select Buildings StringDynamic ProgrammingPrefix Sum	Medium	Dream11 DE Shaw Amazon	67%	51.0%
#2488	Count Subarrays With Median K ArrayHash TablePrefix Sum	Hard	Salesforce Amazon Google	52%	49.0%
#1588	Sum of All Odd Length Subarrays ArrayMathPrefix Sum	Easy	LinkedIn Amazon Google	50%	84.1%
#2536	Increment Submatrices by One ArrayMatrixPrefix Sum	Medium	Adobe Google Meta	42%	73.8%
#1422	Maximum Score After Splitting a String StringPrefix Sum	Easy	Google Meta Amazon	30%	65.1%
#731	My Calendar II ArrayBinary SearchDesignSegment TreePrefix SumOrdered Set	Medium	Apple Google Amazon	30%	63.3%
#2485	Find the Pivot Integer MathPrefix Sum	Easy	Amazon Meta Google	25%	83.8%
#308	Range Sum Query 2D - Mutable ArrayDesignBinary Indexed TreeSegment TreeMatrixSqrt Decomposition	Medium	Bloomberg Google Amazon	25%	45.5%
#3347	Maximum Frequency of an Element After Performing Operations II ArrayBinary SearchSliding WindowSortingPrefix Sum	Hard	Google Amazon Bloomberg	25%	53.9%
#363	Max Sum of Rectangle No Larger Than K ArrayBinary SearchMatrixPrefix SumOrdered Set	Hard	Google Bloomberg Amazon	25%	45.7%
#848	Shifting Letters ArrayStringPrefix Sum	Medium	Microsoft Bloomberg Google	25%	46.3%
#995	Minimum Number of K Consecutive Bit Flips ArrayBit ManipulationQueueSliding WindowPrefix SumBrute-Force Search	Hard	Google Amazon Meta	16%	0.6%
#3756	Concatenate Non-Zero Digits and Multiply by Sum II MathStringPrefix Sum	Medium	Google Amazon Bloomberg	16%	42.9%
#3312	Sorted GCD Pair Queries ArrayHash TableMathBinary SearchCombinatoricsCountingNumber TheoryPrefix SumEuclidean AlgorithmGreatest Common Divisor	Hard	Google Amazon Bloomberg	16%	0.6%
#1420	Build Array Where You Can Find The Maximum Exactly K Comparisons Dynamic ProgrammingPrefix Sum	Hard	Dunzo Google	100%	65.5%
#2121	Intervals Between Identical Elements ArrayHash TablePrefix Sum	Medium	TuSimple Wayve	100%	48.1%
#3709	Design Exam Scores Tracker ArrayBinary SearchDesignPrefix Sum	Medium	Meesho Amazon	92%	0.4%
#2552	Count Increasing Quadruplets ArrayDynamic ProgrammingBinary Indexed TreeEnumerationPrefix Sum	Hard	SAP Deutsche Bank	92%	34.5%
#2955	Number of Same-End Substrings ArrayHash TableStringCountingPrefix Sum	Medium	Sprinklr Google	90%	61.7%
#3070	Count Submatrices with Top-Left Element and Sum Less Than k ArrayMatrixPrefix Sum	Medium	Barclays Google	88%	74.9%
#3077	Maximum Strength of K Disjoint Subarrays ArrayDynamic ProgrammingPrefix Sum	Hard	DE Shaw Amazon	75%	28.1%
#3410	Maximize Subarray Sum After Removing All Occurrences of One Element ArrayHash TableDivide and ConquerDynamic ProgrammingSegment TreePrefix Sum	Hard	Rubrik Google	75%	23.4%
#1589	Maximum Sum Obtained of Any Permutation ArrayGreedySortingPrefix Sum	Medium	PayPal Google	75%	41.2%
#2398	Maximum Number of Robots Within Budget ArrayBinary SearchQueueSliding WindowHeap (Priority Queue)Prefix SumMonotonic Queue	Hard	InMobi Amazon	67%	38.8%
#3900	Longest Balanced Substring After One Swap Hash TableStringPrefix Sum	Medium	Tekion Google	64%	0.1%
#3653	XOR After Range Multiplication Queries I ArrayDivide and ConquerSimulationPrefix Sum	Medium	Infosys Amazon	63%	73.3%
#3655	XOR After Range Multiplication Queries II ArrayDivide and ConquerPrefix Sum	Hard	Infosys Amazon	63%	47.7%
#1829	Maximum XOR for Each Query ArrayBit ManipulationPrefix Sum	Medium	Uber Bloomberg	50%	84.7%
#3413	Maximum Coins From K Consecutive Bags ArrayBinary SearchGreedySliding WindowSortingPrefix Sum	Medium	Amazon Google	47%	25.7%
#3130	Find All Possible Stable Binary Arrays II Dynamic ProgrammingPrefix Sum	Hard	IBM Amazon	42%	58.8%
#2237	Count Positions on Street With Required Brightness ArrayPrefix Sum	Medium	Capital One Google	35%	0.6%
#497	Random Point in Non-overlapping Rectangles ArrayMathBinary SearchReservoir SamplingPrefix SumOrdered SetRandomized	Medium	Uber Google	28%	40.1%
#2025	Maximum Number of Ways to Partition an Array ArrayHash TableCountingEnumerationPrefix Sum	Hard	Salesforce Google	28%	35.9%
#3728	Stable Subarrays With Equal Boundary and Interior Sum ArrayHash TablePrefix Sum	Medium	Microsoft Amazon	27%	26.5%
#3212	Count Submatrices With Equal Frequency of X and Y ArrayMatrixPrefix Sum	Medium	Microsoft Amazon	27%	69.7%
#2391	Minimum Amount of Time to Collect Garbage ArrayStringPrefix Sum	Medium	Microsoft Google	27%	85.1%
#3862	Find the Smallest Balanced Index ArrayPrefix Sum	Medium	Meta Google	25%	19.5%
#2256	Minimum Average Difference ArrayPrefix Sum	Medium	Amazon Meta	25%	44.0%
#2100	Find Good Days to Rob the Bank ArrayDynamic ProgrammingPrefix Sum	Medium	Amazon Google	25%	51.9%
#1525	Number of Good Ways to Split a String Hash TableStringDynamic ProgrammingBit ManipulationPrefix Sum	Medium	Google Amazon	25%	68.5%
#813	Largest Sum of Averages ArrayDynamic ProgrammingPrefix Sum	Medium	Google Amazon	25%	55.2%
#3721	Longest Balanced Subarray II ArrayHash TableDivide and ConquerSegment TreePrefix Sum	Hard	Google Amazon	25%	33.8%
#370	Range Addition ArrayPrefix Sum	Medium	Google Amazon	25%	73.1%
#1915	Number of Wonderful Substrings Hash TableStringBit ManipulationPrefix Sum	Medium	Uber Google	25%	66.6%
#1442	Count Triplets That Can Form Two Arrays of Equal XOR ArrayHash TableMathBit ManipulationPrefix Sum	Medium	Meta Google	13%	84.8%
#3427	Sum of Variable Length Subarrays ArrayPrefix Sum	Easy	Amazon Google	13%	85.8%
#3739	Count Subarrays With Majority Element II ArrayHash TableDivide and ConquerSegment TreeMerge SortPrefix Sum	Hard	Amazon Microsoft	13%	64.9%
#3548	Equal Sum Grid Partition II ArrayHash TableMatrixEnumerationPrefix Sum	Hard	Microsoft Google	13%	39.4%
#2428	Maximum Sum of an Hourglass ArrayMatrixPrefix Sum	Medium	Nutanix	100%	76.4%
#1687	Delivering Boxes from Storage to Ports ArrayDynamic ProgrammingSegment TreeQueueHeap (Priority Queue)Prefix SumMonotonic Queue	Hard	Nutanix	100%	39.9%
#3883	Count Non Decreasing Arrays With Given Digit Sums ArrayDynamic ProgrammingPrefix Sum	Hard	Docusign	100%	41.6%
#1177	Can Make Palindrome from Substring ArrayHash TableStringBit ManipulationPrefix Sum	Medium	Akuna Capital	100%	41.8%
#548	Split Array with Equal Sum ArrayHash TablePrefix Sum	Hard	Alibaba	100%	50.1%
#2505	Bitwise OR of All Subsequence Sums ArrayMathBit ManipulationBrainteaserPrefix Sum	Medium	Zomato	100%	64.1%
#2971	Find Polygon With the Largest Perimeter ArrayGreedySortingPrefix SumPolygons	Medium	Airtel	100%	65.6%
#2838	Maximum Coins Heroes Can Collect ArrayTwo PointersBinary SearchSortingPrefix Sum	Medium	Deutsche Bank	100%	68.8%
#1977	Number of Ways to Separate Numbers StringDynamic ProgrammingPrefix Sum	Hard	Walmart Labs	88%	21.8%
#3179	Find the N-th Value After K Seconds ArrayMathSimulationCombinatoricsPrefix Sum	Medium	Walmart Labs	88%	54.1%
#3628	Maximum Number of Subsequences After One Inserting StringDynamic ProgrammingGreedyPrefix Sum	Medium	DE Shaw	83%	32.1%
#2875	Minimum Size Subarray in Infinite Array ArrayHash TableSliding WindowPrefix Sum	Medium	DE Shaw	77%	32.4%
#2171	Removing Minimum Number of Magic Beans ArrayGreedySortingEnumerationPrefix Sum	Medium	DE Shaw	75%	44.8%
#2234	Maximum Total Beauty of the Gardens ArrayTwo PointersBinary SearchGreedySortingEnumerationPrefix Sum	Hard	Intuit	75%	30.2%
#2489	Number of Substrings With Fixed Ratio Hash TableMathStringPrefix Sum	Medium	Intuit	75%	57.2%
#1872	Stone Game VIII ArrayMathDynamic ProgrammingMinimaxPrefix SumGame TheoryZero-Sum Game	Hard	Infosys	75%	54.2%
#3096	Minimum Levels to Gain More Points ArrayPrefix Sum	Medium	IBM	65%	40.5%
#3251	Find the Count of Monotonic Pairs II ArrayMathDynamic ProgrammingCombinatoricsPrefix Sum	Hard	BNY Mellon	64%	24.9%
#3511	Make a Positive Array ArrayGreedyPrefix Sum	Medium	UKG	63%	36.4%
#2132	Stamping the Grid ArrayGreedyMatrixPrefix Sum	Hard	Rubrik	63%	35.6%
#3015	Count the Number of Houses at a Certain Distance I Breadth-First SearchGraph TheoryPrefix Sum	Medium	Oracle	63%	58.1%
#3017	Count the Number of Houses at a Certain Distance II Graph TheoryPrefix Sum	Hard	Oracle	63%	23.8%
#2640	Find the Score of All Prefixes of an Array ArrayPrefix Sum	Medium	TikTok	63%	73.0%
#3086	Minimum Moves to Pick K Ones ArrayGreedySliding WindowPrefix Sum	Hard	TikTok	63%	21.8%
#3540	Minimum Time to Visit All Houses ArrayPrefix Sum	Medium	Salesforce	63%	69.2%
#3891	Minimum Increase to Maximize Special Indices ArrayDynamic ProgrammingGreedyPrefix Sum	Medium	LinkedIn	50%	19.8%
#2420	Find All Good Indices ArrayDynamic ProgrammingPrefix Sum	Medium	Goldman Sachs	50%	41.1%
#2848	Points That Intersect With Cars ArrayHash TablePrefix Sum	Easy	Uber	50%	73.5%
#2281	Sum of Total Strength of Wizards ArrayStackMonotonic StackPrefix Sum	Hard	Amazon	40%	29.6%
#1983	Widest Pair of Indices With Equal Range Sum ArrayHash TablePrefix Sum	Medium	Microsoft	27%	54.1%
#2015	Average Height of Buildings in Each Segment ArraySortingHeap (Priority Queue)Prefix Sum	Medium	Microsoft	27%	58.7%
#2207	Maximize Number of Subsequences in a String StringGreedyPrefix Sum	Medium	Amazon	25%	36.2%
#2947	Count Beautiful Substrings I Hash TableMathStringEnumerationNumber TheoryPrefix Sum	Medium	Amazon	25%	61.5%
#1621	Number of Sets of K Non-Overlapping Line Segments MathDynamic ProgrammingCombinatoricsPrefix Sum	Medium	Amazon	25%	46.1%
#1788	Maximize the Beauty of the Garden ArrayHash TableGreedyPrefix Sum	Hard	Amazon	25%	65.0%
#2219	Maximum Sum Score of Array ArrayPrefix Sum	Medium	Amazon	25%	62.8%
#2949	Count Beautiful Substrings II Hash TableMathStringNumber TheoryPrefix Sum	Hard	Amazon	25%	27.8%
#3864	Minimum Cost to Partition a Binary String StringDivide and ConquerPrefix Sum	Hard	Amazon	25%	52.6%
#1444	Number of Ways of Cutting a Pizza ArrayDynamic ProgrammingMemoizationMatrixPrefix Sum	Hard	Google	25%	61.6%
#732	My Calendar III Binary SearchDesignSegment TreePrefix SumOrdered Set	Hard	Google	25%	72.0%
#2218	Maximum Value of K Coins From Piles ArrayDynamic ProgrammingPrefix Sum	Hard	Google	25%	60.5%
#1738	Find Kth Largest XOR Coordinate Value ArrayDivide and ConquerBit ManipulationSortingHeap (Priority Queue)MatrixPrefix SumQuickselect	Medium	Google	25%	64.4%
#2478	Number of Beautiful Partitions StringDynamic ProgrammingPrefix Sum	Hard	Google	25%	33.2%
#644	Maximum Average Subarray II ArrayBinary SearchPrefix Sum	Hard	Google	25%	37.8%
#1546	Maximum Number of Non-Overlapping Subarrays With Sum Equals Target ArrayHash TableGreedyPrefix Sum	Medium	Google	25%	49.1%
#1737	Change Minimum Characters to Satisfy One of Three Conditions Hash TableStringCountingPrefix Sum	Medium	Google	25%	38.2%
#1906	Minimum Absolute Difference Queries ArrayPrefix Sum	Medium	Google	25%	45.9%
#2209	Minimum White Tiles After Covering With Carpets StringDynamic ProgrammingPrefix Sum	Hard	Google	25%	39.1%
#3698	Split Array With Minimum Difference ArrayPrefix Sum	Medium	Google	18%	33.6%
#3797	Count Routes to Climb a Rectangular Grid ArrayDynamic ProgrammingMatrixPrefix Sum	Hard	Microsoft	13%	25.1%
#3969	Valid Subarrays With Matching Sum Digits I ArrayHash TableSliding WindowEnumerationPrefix Sum	Medium	Microsoft	13%	46.7%
#3486	Longest Special Path II ArrayHash TableTreeDepth-First SearchPrefix Sum	Hard	Google	13%	19.8%
#798	Smallest Rotation with Highest Score ArrayPrefix Sum	Hard	Google	13%	54.3%
#3538	Merge Operations for Minimum Travel Time ArrayDynamic ProgrammingPrefix Sum	Hard	Google	13%	31.4%
#3361	Shift Distance Between Two Strings ArrayStringPrefix Sum	Medium	Google	13%	53.8%
#3599	Partition Array to Minimize XOR ArrayDynamic ProgrammingBit ManipulationPrefix Sum	Medium	Google	13%	41.6%

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