5.Longest Palindromic Substring
MediumDynamic ProgrammingStringTwo Pointers38.7% acceptance81 companiesVideo
Medium · 305 results
22.Generate Parentheses
MediumBacktrackingDynamic ProgrammingString79.6% acceptance40 companiesVideo
45.Jump Game II
MediumArrayDynamic ProgrammingGreedy43.2% acceptance26 companiesVideo
53.Maximum Subarray
MediumArrayDivide and ConquerDynamic Programming53.7% acceptance64 companiesVideo
55.Jump Game
MediumArrayDynamic ProgrammingGreedy41.2% acceptance33 companiesVideo
62.Unique Paths
MediumCombinatoricsDynamic ProgrammingMath67.3% acceptance21 companiesVideo
63.Unique Paths II
MediumArrayDynamic ProgrammingMatrix44.9% acceptance9 companiesVideo
64.Minimum Path Sum
MediumArrayDynamic ProgrammingMatrix68.6% acceptance17 companiesVideo
72.Edit Distance
MediumDynamic ProgrammingString61.5% acceptance24 companiesVideo
91.Decode Ways
MediumDynamic ProgrammingString38.3% acceptance22 companiesVideo
95.Unique Binary Search Trees II
MediumBacktrackingBinary Search TreeBinary Tree63.3% acceptance5 companiesVideo
96.Unique Binary Search Trees
MediumBinary Search TreeBinary TreeDynamic Programming64.0% acceptance10 companiesVideo
97.Interleaving String
MediumDynamic ProgrammingString45.0% acceptance10 companiesVideo
120.Triangle
MediumArrayDynamic Programming59.9% acceptance11 companiesVideo
122.Best Time to Buy and Sell Stock II
MediumArrayDynamic ProgrammingGreedy71.4% acceptance28 companiesVideo
131.Palindrome Partitioning
MediumBacktrackingDynamic ProgrammingString74.4% acceptance10 companiesVideo
139.Word Break
MediumArrayDynamic ProgrammingHash Table49.8% acceptance32 companiesVideo
152.Maximum Product Subarray
MediumArrayDynamic Programming37.3% acceptance23 companiesVideo
198.House Robber
MediumArrayDynamic Programming53.6% acceptance40 companiesVideo
213.House Robber II
MediumArrayDynamic Programming45.3% acceptance19 companiesVideo
221.Maximal Square
MediumArrayDynamic ProgrammingMatrix50.7% acceptance28 companiesVideo
241.Different Ways to Add Parentheses
MediumDynamic ProgrammingMathMemoization73.7% acceptance6 companiesVideo
256.Paint House
MediumArrayDynamic Programming64.3% acceptance8 companiesPremium elsewhere, free hereVideo
264.Ugly Number II
MediumDynamic ProgrammingHash TableHeap (Priority Queue)49.7% acceptance9 companiesVideo
276.Paint Fence
MediumDynamic Programming48.3% acceptance4 companiesPremium elsewhere, free hereVideo
279.Perfect Squares
MediumBreadth-First SearchDynamic ProgrammingMath57.0% acceptance12 companiesVideo
294.Flip Game II
MediumBacktrackingDynamic ProgrammingGame Theory52.2% acceptance2 companiesPremium elsewhere, free hereVideo
300.Longest Increasing Subsequence
MediumArrayBinary SearchDynamic Programming59.8% acceptance30 companiesVideo
309.Best Time to Buy and Sell Stock with Cooldown
MediumArrayDynamic Programming62.4% acceptance8 companiesVideo
313.Super Ugly Number
MediumArrayDynamic ProgrammingMath46.6% acceptance5 companiesVideo
322.Coin Change
MediumArrayBreadth-First SearchDynamic Programming49.3% acceptance40 companiesVideo
333.Largest BST Subtree
MediumBinary Search TreeBinary TreeDepth-First Search45.8% acceptance2 companiesPremium elsewhere, free hereVideo
337.House Robber III
MediumBinary TreeDepth-First SearchDynamic Programming56.3% acceptance13 companiesVideo
343.Integer Break
MediumDynamic ProgrammingMath62.6% acceptance6 companiesVideo
351.Android Unlock Patterns
MediumBacktrackingBit ManipulationBitmask53.8% acceptance1 companyPremium elsewhere, free hereVideo
357.Count Numbers with Unique Digits
MediumBacktrackingDynamic ProgrammingMath56.1% acceptance5 companiesVideo
361.Bomb Enemy
MediumArrayDynamic ProgrammingMatrix52.8% acceptance2 companiesPremium elsewhere, free hereVideo
368.Largest Divisible Subset
MediumArrayDynamic ProgrammingMath50.1% acceptance6 companiesVideo
375.Guess Number Higher or Lower II
MediumDynamic ProgrammingGame TheoryMath53.8% acceptance3 companiesVideo
376.Wiggle Subsequence
MediumArrayDynamic ProgrammingGreedy49.9% acceptance1 companyVideo
377.Combination Sum IV
MediumArrayDynamic Programming55.0% acceptance7 companiesVideo
396.Rotate Function
MediumArrayDynamic ProgrammingMath54.0% acceptance6 companiesVideo
397.Integer Replacement
MediumBit ManipulationDynamic ProgrammingGreedy37.9% acceptance4 companiesVideo
413.Arithmetic Slices
MediumArrayDynamic ProgrammingSliding Window65.0% acceptance7 companiesVideo
416.Partition Equal Subset Sum
MediumArrayDynamic Programming49.9% acceptance16 companiesVideo
418.Sentence Screen Fitting
MediumArrayDynamic ProgrammingString36.3% acceptance1 companyPremium elsewhere, free hereVideo
435.Non-overlapping Intervals
MediumArrayDynamic ProgrammingGreedy57.5% acceptance18 companiesVideo
464.Can I Win
MediumBit ManipulationBitmaskDynamic Programming31.7% acceptance4 companiesVideo
467.Unique Substrings in Wraparound String
MediumDynamic ProgrammingString44.0% acceptance2 companiesVideo
473.Matchsticks to Square
MediumArrayBacktrackingBit Manipulation42.3% acceptance9 companiesVideo
Showing 1–50 of 305
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.