Interview Prep/Companies/Citadel

Citadel

100 questions tracked88 with solutions

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Frequency scoreSorted highest → lowest frequency✓ Our Solution = we have a detailed walkthrough

Showing 100 of 100 questions

MediumLongest Non-decreasing Subarray From Two Arrays✓ Our Solution

100

ArrayDynamic Programming

LeetCode ↗30% acc.

HardBinary Tree Maximum Path Sum✓ Our Solution

Dynamic ProgrammingTreeDepth-First SearchBinary Tree

LeetCode ↗41% acc.

MediumDelete and Earn✓ Our Solution

ArrayHash TableDynamic Programming

LeetCode ↗57% acc.

MediumMinimum Knight Moves

Breadth-First Search

LeetCode ↗41% acc.

MediumPalindromic Substrings✓ Our Solution

Two PointersStringDynamic Programming

LeetCode ↗72% acc.

HardSliding Window Maximum✓ Our Solution

ArrayQueueSliding WindowHeap (Priority Queue)+1

LeetCode ↗48% acc.

HardCount Palindromic Subsequences✓ Our Solution

StringDynamic Programming

LeetCode ↗39% acc.

MediumMinimum Equal Sum of Two Arrays After Replacing Zeros✓ Our Solution

ArrayGreedy

LeetCode ↗50% acc.

HardLFU Cache✓ Our Solution

Hash TableLinked ListDesignDoubly-Linked List

LeetCode ↗47% acc.

HardMinimum Operations to Make Numbers Non-positive

ArrayBinary Search

LeetCode ↗42% acc.

MediumNumber of Good Binary Strings

Dynamic Programming

LeetCode ↗52% acc.

MediumMaximum Total Damage With Spell Casting✓ Our Solution

ArrayHash TableTwo PointersBinary Search+3

LeetCode ↗28% acc.

MediumMaximum Length of Repeated Subarray✓ Our Solution

ArrayBinary SearchDynamic ProgrammingSliding Window+2

LeetCode ↗51% acc.

MediumLRU Cache✓ Our Solution

Hash TableLinked ListDesignDoubly-Linked List

LeetCode ↗45% acc.

HardMinimum Costs Using the Train Line

ArrayDynamic Programming

LeetCode ↗78% acc.

HardBest Position for a Service Centre✓ Our Solution

ArrayMathGeometryRandomized

LeetCode ↗35% acc.

MediumEvaluate Division✓ Our Solution

ArrayStringDepth-First SearchBreadth-First Search+3

LeetCode ↗63% acc.

MediumFirst Completely Painted Row or Column✓ Our Solution

ArrayHash TableMatrix

LeetCode ↗64% acc.

MediumLongest String Chain✓ Our Solution

ArrayHash TableTwo PointersString+2

LeetCode ↗62% acc.

MediumMerge Intervals✓ Our Solution

ArraySorting

LeetCode ↗49% acc.

EasyBest Time to Buy and Sell Stock✓ Our Solution

ArrayDynamic Programming

LeetCode ↗55% acc.

HardSerialize and Deserialize Binary Tree✓ Our Solution

StringTreeDepth-First SearchBreadth-First Search+2

LeetCode ↗59% acc.

MediumFind the Duplicate Number✓ Our Solution

ArrayTwo PointersBinary SearchBit Manipulation

LeetCode ↗63% acc.

MediumEvaluate Reverse Polish Notation✓ Our Solution

ArrayMathStack

LeetCode ↗55% acc.

MediumInsert Delete GetRandom O(1)✓ Our Solution

ArrayHash TableMathDesign+1

LeetCode ↗55% acc.

HardSudoku Solver✓ Our Solution

ArrayHash TableBacktrackingMatrix

LeetCode ↗64% acc.

MediumLength of Longest Subarray With at Most K Frequency✓ Our Solution

ArrayHash TableSliding Window

LeetCode ↗56% acc.

HardParallel Courses III✓ Our Solution

ArrayDynamic ProgrammingGraphTopological Sort

LeetCode ↗67% acc.

MediumNumber of Islands✓ Our Solution

ArrayDepth-First SearchBreadth-First SearchUnion Find+1

LeetCode ↗62% acc.

HardCouples Holding Hands✓ Our Solution

GreedyDepth-First SearchBreadth-First SearchUnion Find+1

LeetCode ↗58% acc.

HardFind Median from Data Stream✓ Our Solution

Two PointersDesignSortingHeap (Priority Queue)+1

LeetCode ↗53% acc.

MediumGroup Anagrams✓ Our Solution

ArrayHash TableStringSorting

LeetCode ↗71% acc.

MediumValidate Binary Search Tree✓ Our Solution

TreeDepth-First SearchBinary Search TreeBinary Tree

LeetCode ↗34% acc.

MediumMeeting Scheduler

ArrayTwo PointersSorting

LeetCode ↗55% acc.

HardEmployee Free Time

ArrayLine SweepSortingHeap (Priority Queue)

LeetCode ↗73% acc.

HardMerge k Sorted Lists✓ Our Solution

Linked ListDivide and ConquerHeap (Priority Queue)Merge Sort

LeetCode ↗57% acc.

MediumPermutations✓ Our Solution

ArrayBacktracking

LeetCode ↗81% acc.

HardRobot Room Cleaner

BacktrackingInteractive

LeetCode ↗78% acc.

MediumBinary Tree Zigzag Level Order Traversal✓ Our Solution

TreeBreadth-First SearchBinary Tree

LeetCode ↗62% acc.

HardDesign Search Autocomplete System

StringDepth-First SearchDesignTrie+3

LeetCode ↗49% acc.

HardN-Queens✓ Our Solution

ArrayBacktracking

LeetCode ↗73% acc.

EasyFizz Buzz✓ Our Solution

MathStringSimulation

LeetCode ↗74% acc.

MediumBest Time to Buy and Sell Stock II✓ Our Solution

ArrayDynamic ProgrammingGreedy

LeetCode ↗70% acc.

HardRegular Expression Matching✓ Our Solution

StringDynamic ProgrammingRecursion

LeetCode ↗29% acc.

HardBest Time to Buy and Sell Stock III✓ Our Solution

ArrayDynamic Programming

LeetCode ↗51% acc.

MediumSearch Suggestions System✓ Our Solution

ArrayStringBinary SearchTrie+2

LeetCode ↗65% acc.

MediumCombination Sum✓ Our Solution

ArrayBacktracking

LeetCode ↗75% acc.

MediumDesign Circular Queue✓ Our Solution

ArrayLinked ListDesignQueue

LeetCode ↗53% acc.

HardTrapping Rain Water✓ Our Solution

ArrayTwo PointersDynamic ProgrammingStack+1

LeetCode ↗65% acc.

MediumWord Search✓ Our Solution

ArrayStringBacktrackingDepth-First Search+1

LeetCode ↗45% acc.

HardDesign Excel Sum Formula

ArrayHash TableStringGraph+3

LeetCode ↗43% acc.

EasyClimbing Stairs✓ Our Solution

MathDynamic ProgrammingMemoization

LeetCode ↗54% acc.

MediumLetter Combinations of a Phone Number✓ Our Solution

Hash TableStringBacktracking

LeetCode ↗64% acc.

EasySqrt(x)✓ Our Solution

MathBinary Search

LeetCode ↗40% acc.

MediumImplement Trie (Prefix Tree)✓ Our Solution

Hash TableStringDesignTrie

LeetCode ↗68% acc.

EasyMoving Average from Data Stream

ArrayDesignQueueData Stream

LeetCode ↗80% acc.

HardSort Items by Groups Respecting Dependencies✓ Our Solution

Depth-First SearchBreadth-First SearchGraphTopological Sort

LeetCode ↗66% acc.

MediumDesign Front Middle Back Queue✓ Our Solution

ArrayLinked ListDesignQueue+1

LeetCode ↗56% acc.

HardMedian of Two Sorted Arrays✓ Our Solution

ArrayBinary SearchDivide and Conquer

LeetCode ↗44% acc.

HardFind Servers That Handled Most Number of Requests✓ Our Solution

ArrayGreedyHeap (Priority Queue)Ordered Set

LeetCode ↗44% acc.

HardLongest Increasing Path in a Matrix✓ Our Solution

ArrayDynamic ProgrammingDepth-First SearchBreadth-First Search+4

LeetCode ↗55% acc.

MediumHouse Robber✓ Our Solution

ArrayDynamic Programming

LeetCode ↗52% acc.

MediumMaximal Square✓ Our Solution

ArrayDynamic ProgrammingMatrix

LeetCode ↗49% acc.

Medium3Sum✓ Our Solution

ArrayTwo PointersSorting

LeetCode ↗37% acc.

MediumPerfect Squares✓ Our Solution

MathDynamic ProgrammingBreadth-First Search

LeetCode ↗56% acc.

MediumMinimum Height Trees✓ Our Solution

Depth-First SearchBreadth-First SearchGraphTopological Sort

LeetCode ↗42% acc.

HardAlien Dictionary

ArrayStringDepth-First SearchBreadth-First Search+2

LeetCode ↗37% acc.

MediumCount Ways To Build Good Strings✓ Our Solution

Dynamic Programming

LeetCode ↗59% acc.

HardTransform to Chessboard✓ Our Solution

ArrayMathBit ManipulationMatrix

LeetCode ↗51% acc.

MediumBest Time to Buy and Sell Stock with Transaction Fee✓ Our Solution

ArrayDynamic ProgrammingGreedy

LeetCode ↗71% acc.

MediumOpen the Lock✓ Our Solution

ArrayHash TableStringBreadth-First Search

LeetCode ↗61% acc.

MediumKoko Eating Bananas✓ Our Solution

ArrayBinary Search

LeetCode ↗49% acc.

MediumPopulating Next Right Pointers in Each Node II✓ Our Solution

Linked ListTreeDepth-First SearchBreadth-First Search+1

LeetCode ↗56% acc.

HardMax Points on a Line✓ Our Solution

ArrayHash TableMathGeometry

LeetCode ↗29% acc.

MediumInteger to Roman✓ Our Solution

Hash TableMathString

LeetCode ↗69% acc.

MediumPermutations II✓ Our Solution

ArrayBacktrackingSorting

LeetCode ↗62% acc.

MediumPow(x, n)✓ Our Solution

MathRecursion

LeetCode ↗37% acc.

MediumSimplify Path✓ Our Solution

StringStack

LeetCode ↗48% acc.

MediumContainer With Most Water✓ Our Solution

ArrayTwo PointersGreedy

LeetCode ↗58% acc.

MediumRotting Oranges✓ Our Solution

ArrayBreadth-First SearchMatrix

LeetCode ↗57% acc.

MediumLongest Increasing Subsequence✓ Our Solution

ArrayBinary SearchDynamic Programming

LeetCode ↗58% acc.

HardRank Transform of a Matrix✓ Our Solution

ArrayUnion FindGraphTopological Sort+2

LeetCode ↗41% acc.

MediumPaint House

ArrayDynamic Programming

LeetCode ↗64% acc.

MediumSubarray Sums Divisible by K✓ Our Solution

ArrayHash TablePrefix Sum

LeetCode ↗56% acc.

MediumSearch a 2D Matrix II✓ Our Solution

ArrayBinary SearchDivide and ConquerMatrix

LeetCode ↗55% acc.

HardBest Time to Buy and Sell Stock IV✓ Our Solution

ArrayDynamic Programming

LeetCode ↗47% acc.

HardInsert Delete GetRandom O(1) - Duplicates allowed✓ Our Solution

ArrayHash TableMathDesign+1

LeetCode ↗36% acc.

HardWord Ladder II✓ Our Solution

Hash TableStringBacktrackingBreadth-First Search

LeetCode ↗27% acc.

HardBus Routes✓ Our Solution

ArrayHash TableBreadth-First Search

LeetCode ↗47% acc.

MediumCourse Schedule✓ Our Solution

Depth-First SearchBreadth-First SearchGraphTopological Sort

LeetCode ↗49% acc.

MediumReorganize String✓ Our Solution

Hash TableStringGreedySorting+2

LeetCode ↗56% acc.

MediumLongest Common Subsequence✓ Our Solution

StringDynamic Programming

LeetCode ↗58% acc.

MediumEgg Drop With 2 Eggs and N Floors✓ Our Solution

MathDynamic Programming

LeetCode ↗74% acc.

MediumCourse Schedule II✓ Our Solution

Depth-First SearchBreadth-First SearchGraphTopological Sort

LeetCode ↗53% acc.

MediumPopulating Next Right Pointers in Each Node✓ Our Solution

Linked ListTreeDepth-First SearchBreadth-First Search+1

LeetCode ↗65% acc.

MediumKnight Probability in Chessboard✓ Our Solution

Dynamic Programming

LeetCode ↗57% acc.

MediumAsteroid Collision✓ Our Solution

ArrayStackSimulation

LeetCode ↗46% acc.

HardThe Skyline Problem✓ Our Solution

ArrayDivide and ConquerBinary Indexed TreeSegment Tree+3

LeetCode ↗44% acc.

HardBasic Calculator✓ Our Solution

MathStringStackRecursion

LeetCode ↗46% acc.

100

MediumCount Number of Maximum Bitwise-OR Subsets✓ Our Solution

ArrayBacktrackingBit ManipulationEnumeration

LeetCode ↗88% acc.