247.Strobogrammatic Number II
MediumArrayRecursionString53.5% acceptance2 companiesPremium elsewhere, free hereVideo
With video · 2,100 results
248.Strobogrammatic Number III
HardArrayRecursionString42.3% acceptancePremium elsewhere, free hereVideo
249.Group Shifted Strings
MediumArrayHash TableString67.8% acceptance4 companiesPremium elsewhere, free hereVideo
251.Flatten 2D Vector
MediumArrayDesignIterator50.5% acceptance4 companiesPremium elsewhere, free hereVideo
252.Meeting Rooms
EasyArraySorting59.4% acceptance10 companiesPremium elsewhere, free hereVideo
253.Meeting Rooms II
MediumArrayGreedyHeap (Priority Queue)52.6% acceptance42 companiesPremium elsewhere, free hereVideo
255.Verify Preorder Sequence in Binary Search Tree
MediumArrayBinary Search TreeBinary Tree51.7% acceptance5 companiesPremium elsewhere, free hereVideo
256.Paint House
MediumArrayDynamic Programming64.3% acceptance8 companiesPremium elsewhere, free hereVideo
259.3Sum Smaller
MediumArrayBinary SearchSorting51.4% acceptance7 companiesPremium elsewhere, free hereVideo
260.Single Number III
MediumArrayBit Manipulation70.2% acceptance7 companiesVideo
265.Paint House II
HardArrayDynamic Programming57.0% acceptance2 companiesPremium elsewhere, free hereVideo
268.Missing Number
EasyArrayBinary SearchBit Manipulation72.4% acceptance19 companiesVideo
269.Alien Dictionary
HardArrayBreadth-First SearchDepth-First Search37.1% acceptance18 companiesPremium elsewhere, free hereVideo
271.Encode and Decode Strings
MediumArrayDesignString51.9% acceptance11 companiesPremium elsewhere, free hereVideo
274.H-Index
MediumArrayCounting SortSorting41.8% acceptance8 companiesVideo
275.H-Index II
MediumArrayBinary Search40.0% acceptance1 companyVideo
280.Wiggle Sort
MediumArrayGreedySorting68.5% acceptance4 companiesPremium elsewhere, free hereVideo
281.Zigzag Iterator
MediumArrayDesignIterator67.1% acceptance5 companiesPremium elsewhere, free hereVideo
283.Move Zeroes
EasyArrayTwo Pointers64.3% acceptance46 companiesVideo
284.Peeking Iterator
MediumArrayDesignIterator61.9% acceptance3 companiesVideo
286.Walls and Gates
MediumArrayBreadth-First SearchMatrix63.9% acceptance11 companiesPremium elsewhere, free hereVideo
287.Find the Duplicate Number
MediumArrayBinary SearchBit Manipulation64.7% acceptance22 companiesVideo
288.Unique Word Abbreviation
MediumArrayDesignHash Table28.1% acceptance1 companyPremium elsewhere, free hereVideo
289.Game of Life
MediumArrayMatrixSimulation73.0% acceptance15 companiesVideo
296.Best Meeting Point
HardArrayMathMatrix61.1% acceptance9 companiesPremium elsewhere, free hereVideo
300.Longest Increasing Subsequence
MediumArrayBinary SearchDynamic Programming59.8% acceptance30 companiesVideo
302.Smallest Rectangle Enclosing Black Pixels
HardArrayBinary SearchBreadth-First Search60.9% acceptance1 companyPremium elsewhere, free hereVideo
303.Range Sum Query - Immutable
EasyArrayDesignPrefix Sum73.5% acceptance8 companiesVideo
304.Range Sum Query 2D - Immutable
MediumArrayDesignMatrix59.2% acceptance10 companiesVideo
305.Number of Islands II
HardArrayHash TableUnion Find40.5% acceptance10 companiesPremium elsewhere, free hereVideo
307.Range Sum Query - Mutable
MediumArrayBinary Indexed TreeDesign43.9% acceptance4 companiesVideo
308.Range Sum Query 2D - Mutable
MediumArrayBinary Indexed TreeDesign46.0% acceptance3 companiesPremium elsewhere, free hereVideo
309.Best Time to Buy and Sell Stock with Cooldown
MediumArrayDynamic Programming62.4% acceptance8 companiesVideo
311.Sparse Matrix Multiplication
MediumArrayHash TableMatrix69.3% acceptance9 companiesPremium elsewhere, free hereVideo
312.Burst Balloons
HardArrayDynamic Programming64.3% acceptance15 companiesVideo
313.Super Ugly Number
MediumArrayDynamic ProgrammingMath46.6% acceptance5 companiesVideo
315.Count of Smaller Numbers After Self
HardArrayBinary Indexed TreeBinary Search44.0% acceptance6 companiesVideo
317.Shortest Distance from All Buildings
HardArrayBreadth-First SearchMatrix44.9% acceptance15 companiesPremium elsewhere, free hereVideo
318.Maximum Product of Word Lengths
MediumArrayBit ManipulationString61.7% acceptance2 companiesVideo
321.Create Maximum Number
HardArrayGreedyMonotonic Stack37.3% acceptance7 companiesVideo
322.Coin Change
MediumArrayBreadth-First SearchDynamic Programming49.3% acceptance40 companiesVideo
324.Wiggle Sort II
MediumArrayDivide and ConquerGreedy38.4% acceptance4 companiesVideo
325.Maximum Size Subarray Sum Equals k
MediumArrayHash TablePrefix Sum50.8% acceptance8 companiesPremium elsewhere, free hereVideo
327.Count of Range Sum
HardArrayBinary Indexed TreeBinary Search40.3% acceptance5 companiesVideo
329.Longest Increasing Path in a Matrix
HardArrayBreadth-First SearchDepth-First Search57.0% acceptance16 companiesVideo
330.Patching Array
HardArrayGreedy54.7% acceptance4 companiesVideo
334.Increasing Triplet Subsequence
MediumArrayGreedy39.3% acceptance7 companiesVideo
335.Self Crossing
HardArrayGeometryMath36.9% acceptance1 companyVideo
336.Palindrome Pairs
HardArrayHash TableString37.7% acceptance8 companiesVideo
346.Moving Average from Data Stream
EasyArrayData StreamDesign80.2% acceptance11 companiesPremium elsewhere, free hereVideo
Showing 101–150 of 2,100
How to use these solutions
Each solution breaks the problem into approaches, usually from brute force to the best one, and explains why each works. Code comes in Python, Java, C++ and other languages. Knowing why an approach works matters more in an interview than remembering the code.
- Try the problem first. Give it at least 20 minutes before you open the solution.
- Read every approach. The brute force shows you the problem; the faster ones show the pattern.
- Check the complexity. Note the time and space of each approach and what makes the difference.
- Write it yourself. Close the solution and code it from memory in the editor.
- Come back in a week. Solving it again later is what makes the pattern stick.