229.Majority Element II
MediumArrayCountingHash Table56.5% acceptance9 companiesVideo
Medium · With video · 105 results
299.Bulls and Cows
MediumCountingHash TableString52.9% acceptance7 companiesVideo
347.Top K Frequent Elements
MediumArrayBucket SortCounting67.3% acceptance53 companiesVideo
451.Sort Characters By Frequency
MediumBucket SortCountingHash Table75.8% acceptance16 companiesVideo
621.Task Scheduler
MediumArrayCountingGreedy64.0% acceptance24 companiesVideo
692.Top K Frequent Words
MediumBucket SortCountingHash Table60.6% acceptance23 companiesVideo
767.Reorganize String
MediumCountingGreedyHash Table57.5% acceptance20 companiesVideo
811.Subdomain Visit Count
MediumArrayCountingHash Table77.2% acceptance4 companiesVideo
869.Reordered Power of 2
MediumCountingEnumerationHash Table66.0% acceptance5 companiesVideo
900.RLE Iterator
MediumArrayCountingDesign59.6% acceptance2 companiesVideo
923.3Sum With Multiplicity
MediumArrayCountingHash Table46.2% acceptance4 companiesVideo
945.Minimum Increment to Make Array Unique
MediumArrayCountingGreedy60.7% acceptance7 companiesVideo
1010.Pairs of Songs With Total Durations Divisible by 60
MediumArrayCountingHash Table53.6% acceptance7 companiesVideo
1054.Distant Barcodes
MediumArrayCountingGreedy49.3% acceptance2 companiesVideo
1079.Letter Tile Possibilities
MediumBacktrackingCountingHash Table83.5% acceptance5 companiesVideo
1090.Largest Values From Labels
MediumArrayCountingGreedy64.7% acceptance1 companyVideo
1198.Find Smallest Common Element in All Rows
MediumArrayBinary SearchCounting76.5% acceptance2 companiesPremium elsewhere, free hereVideo
1267.Count Servers that Communicate
MediumArrayBreadth-First SearchCounting73.5% acceptance6 companiesVideo
1347.Minimum Number of Steps to Make Two Strings Anagram
MediumCountingHash TableString82.6% acceptance10 companiesVideo
1366.Rank Teams by Votes
MediumArrayCountingHash Table60.1% acceptance7 companiesVideo
1400.Construct K Palindrome Strings
MediumCountingGreedyHash Table68.6% acceptance6 companiesVideo
1419.Minimum Number of Frogs Croaking
MediumCountingString51.2% acceptance2 companiesVideo
1481.Least Number of Unique Integers after K Removals
MediumArrayCountingGreedy63.8% acceptance7 companiesVideo
1497.Check If Array Pairs Are Divisible by k
MediumArrayCountingHash Table46.2% acceptance8 companiesVideo
1519.Number of Nodes in the Sub-Tree With the Same Label
MediumBreadth-First SearchCountingDepth-First Search55.5% acceptance2 companiesVideo
1612.Check If Two Expression Trees are Equivalent
MediumBinary TreeCountingDepth-First Search71.8% acceptance1 companyPremium elsewhere, free hereVideo
1657.Determine if Two Strings Are Close
MediumCountingHash TableSorting54.2% acceptance7 companiesVideo
1726.Tuple with Same Product
MediumArrayCountingHash Table70.1% acceptance5 companiesVideo
1737.Change Minimum Characters to Satisfy One of Three Conditions
MediumCountingHash TablePrefix Sum38.4% acceptance1 companyVideo
1775.Equal Sum Arrays With Minimum Number of Operations
MediumArrayCountingGreedy54.6% acceptance1 companyVideo
1781.Sum of Beauty of All Substrings
MediumCountingHash TableString74.9% acceptance6 companiesVideo
1814.Count Nice Pairs in an Array
MediumArrayCountingHash Table48.6% acceptance6 companiesVideo
1940.Longest Common Subsequence Between Sorted Arrays
MediumArrayCountingHash Table81.3% acceptance1 companyPremium elsewhere, free hereVideo
2001.Number of Pairs of Interchangeable Rectangles
MediumArrayCountingHash Table53.1% acceptance2 companiesVideo
2013.Detect Squares
MediumArrayCountingDesign53.0% acceptance4 companiesVideo
2023.Number of Pairs of Strings With Concatenation Equal to Target
MediumArrayCountingHash Table75.6% acceptance2 companiesVideo
2029.Stone Game IX
MediumArrayCountingGame Theory57.6% acceptance1 companyVideo
2067.Number of Equal Count Substrings
MediumCountingPrefix SumString45.1% acceptance1 companyPremium elsewhere, free hereVideo
2083.Substrings That Begin and End With the Same Letter
MediumCountingHash TableMath74.1% acceptancePremium elsewhere, free hereVideo
2131.Longest Palindrome by Concatenating Two Letter Words
MediumArrayCountingGreedy53.5% acceptance6 companiesVideo
2150.Find All Lonely Numbers in the Array
MediumArrayCountingHash Table64.0% acceptance2 companiesVideo
2168.Unique Substrings With Equal Digit Frequency
MediumCountingHash FunctionHash Table64.6% acceptance1 companyPremium elsewhere, free hereVideo
2170.Minimum Operations to Make the Array Alternating
MediumArrayCountingGreedy35.7% acceptance2 companiesVideo
2182.Construct String With Repeat Limit
MediumCountingGreedyHash Table70.9% acceptance5 companiesVideo
2186.Minimum Number of Steps to Make Two Strings Anagram II
MediumCountingHash TableString73.3% acceptance1 companyVideo
2225.Find Players With Zero or One Losses
MediumArrayCountingHash Table72.4% acceptance4 companiesVideo
2244.Minimum Rounds to Complete All Tasks
MediumArrayCountingGreedy63.5% acceptance2 companiesVideo
2268.Minimum Number of Keypresses
MediumCountingGreedyHash Table71.2% acceptance1 companyPremium elsewhere, free hereVideo
2275.Largest Combination With Bitwise AND Greater Than Zero
MediumArrayBit ManipulationCounting81.0% acceptance4 companiesVideo
2284.Sender With Largest Word Count
MediumArrayCountingHash Table60.2% acceptance1 companyVideo
Showing 1–50 of 105
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.