15.3Sum
MediumArraySortingTwo Pointers40.1% acceptance57 companiesVideo
Medium · 294 results
16.3Sum Closest
MediumArraySortingTwo Pointers47.4% acceptance11 companiesVideo
18.4Sum
MediumArraySortingTwo Pointers42.0% acceptance20 companiesVideo
49.Group Anagrams
MediumArrayHash TableSorting73.0% acceptance87 companiesVideo
56.Merge Intervals
MediumArraySorting52.6% acceptance112 companiesVideo
75.Sort Colors
MediumArraySortingTwo Pointers69.9% acceptance37 companiesVideo
147.Insertion Sort List
MediumLinked ListSorting60.5% acceptance5 companiesVideo
148.Sort List
MediumDivide and ConquerLinked ListMerge Sort65.2% acceptance9 companiesVideo
164.Maximum Gap
MediumArrayBucket SortRadix Sort53.4% acceptance7 companiesVideo
179.Largest Number
MediumArrayGreedySorting43.9% acceptance23 companiesVideo
215.Kth Largest Element in an Array
MediumArrayDivide and ConquerHeap (Priority Queue)69.4% acceptance41 companiesVideo
229.Majority Element II
MediumArrayCountingHash Table56.5% acceptance9 companiesVideo
253.Meeting Rooms II
MediumArrayGreedyHeap (Priority Queue)52.6% acceptance42 companiesPremium elsewhere, free hereVideo
259.3Sum Smaller
MediumArrayBinary SearchSorting51.4% acceptance7 companiesPremium elsewhere, free hereVideo
274.H-Index
MediumArrayCounting SortSorting41.8% acceptance8 companiesVideo
280.Wiggle Sort
MediumArrayGreedySorting68.5% acceptance4 companiesPremium elsewhere, free hereVideo
314.Binary Tree Vertical Order Traversal
MediumBinary TreeBreadth-First SearchDepth-First Search57.8% acceptance9 companiesPremium elsewhere, free hereVideo
324.Wiggle Sort II
MediumArrayDivide and ConquerGreedy38.4% acceptance4 companiesVideo
347.Top K Frequent Elements
MediumArrayBucket SortCounting67.3% acceptance53 companiesVideo
360.Sort Transformed Array
MediumArrayMathSorting58.0% acceptance3 companiesPremium elsewhere, free hereVideo
368.Largest Divisible Subset
MediumArrayDynamic ProgrammingMath50.1% acceptance6 companiesVideo
378.Kth Smallest Element in a Sorted Matrix
MediumArrayBinary SearchHeap (Priority Queue)65.1% acceptance10 companiesVideo
406.Queue Reconstruction by Height
MediumArrayBinary Indexed TreeSegment Tree75.2% acceptance5 companiesVideo
435.Non-overlapping Intervals
MediumArrayDynamic ProgrammingGreedy57.5% acceptance18 companiesVideo
436.Find Right Interval
MediumArrayBinary SearchSorting56.7% acceptance4 companiesVideo
451.Sort Characters By Frequency
MediumBucket SortCountingHash Table75.8% acceptance16 companiesVideo
452.Minimum Number of Arrows to Burst Balloons
MediumArrayGreedySorting61.9% acceptance8 companiesVideo
462.Minimum Moves to Equal Array Elements II
MediumArrayMathSorting62.2% acceptance5 companiesVideo
475.Heaters
MediumArrayBinary SearchSorting42.9% acceptance12 companiesVideo
522.Longest Uncommon Subsequence II
MediumArrayHash TableSorting45.8% acceptance1 companyVideo
524.Longest Word in Dictionary through Deleting
MediumArraySortingString53.2% acceptance2 companiesVideo
532.K-diff Pairs in an Array
MediumArrayBinary SearchHash Table46.3% acceptance8 companiesVideo
539.Minimum Time Difference
MediumArrayMathSorting62.7% acceptance9 companiesVideo
581.Shortest Unsorted Continuous Subarray
MediumArrayGreedyMonotonic Stack38.7% acceptance9 companiesVideo
611.Valid Triangle Number
MediumArrayBinary SearchGreedy57.4% acceptance9 companiesVideo
621.Task Scheduler
MediumArrayCountingGreedy64.0% acceptance24 companiesVideo
646.Maximum Length of Pair Chain
MediumArrayDynamic ProgrammingGreedy62.2% acceptance2 companiesVideo
658.Find K Closest Elements
MediumArrayBinary SearchHeap (Priority Queue)50.1% acceptance18 companiesVideo
692.Top K Frequent Words
MediumBucket SortCountingHash Table60.6% acceptance23 companiesVideo
720.Longest Word in Dictionary
MediumArrayHash TableSorting55.2% acceptance3 companiesVideo
721.Accounts Merge
MediumArrayBreadth-First SearchDepth-First Search62.2% acceptance17 companiesVideo
767.Reorganize String
MediumCountingGreedyHash Table57.5% acceptance20 companiesVideo
769.Max Chunks To Make Sorted
MediumArrayGreedyMonotonic Stack64.1% acceptance7 companiesVideo
786.K-th Smallest Prime Fraction
MediumArrayBinary SearchHeap (Priority Queue)69.0% acceptance1 companyVideo
791.Custom Sort String
MediumHash TableSortingString72.3% acceptance5 companiesVideo
792.Number of Matching Subsequences
MediumArrayBinary SearchDynamic Programming50.8% acceptance9 companiesVideo
823.Binary Trees With Factors
MediumArrayDynamic ProgrammingHash Table52.9% acceptance2 companiesVideo
825.Friends Of Appropriate Ages
MediumArrayBinary SearchSorting49.9% acceptance3 companiesVideo
826.Most Profit Assigning Work
MediumArrayBinary SearchGreedy56.4% acceptance5 companiesVideo
833.Find And Replace in String
MediumArrayHash TableSorting50.9% acceptance2 companiesVideo
Showing 1–50 of 294
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.