Striver's SDE Sheet

The SDE sheet is Striver’s compressed list: 191 problems arranged as a 31-day plan, assuming you already know the data structures. Days 28 to 31 cover operating systems, DBMS, networks and system design, which are outside this course’s scope and appear here as empty steps.

Use it if you have already worked a full sheet and want a structured revision pass with a deadline attached. The day boundaries are useful precisely because they force you to stop.

Track it here

Your progress is shared with every other list on this site — tick a problem off here and it is ticked off on its pattern page and in every other sheet that includes it. That is the point of tracking them in one place.

Striver's SDE Sheet

by Raj Vikramaditya (Striver) · original sheet

191 problems

The 31-day condensed version. Assumes you already know the data structures; use it as a revision pass, not a first pass. Per-day problem counts are not transcribed here (only the 191 total is published as a firm number), so each day maps to the pages that cover it rather than to a fixed quota.

How this one is mapped. Striver's SDE Sheet publishes steps rather than a LeetCode-only problem list, and a good number of its problems live on GeeksforGeeks or Coding Ninjas rather than LeetCode. So each step below is matched to the pages on this site that teach it, and the problems shown are this site's LeetCode equivalents for that step — close to the original, not identical to it. Follow the link above for the canonical list.

398 problems

97 easy251 medium50 hard

AllEasyMediumHard

Unsolved onlyExportImportReset

▾Arrays part 1 · 1616

• ○1Two Sumeasyamazongooglemetamicrosoftapplebloomberg
• ○121Best Time to Buy and Sell Stockeasyamazonmetamicrosoftbloomberg
• ○169Majority Elementeasy
• ○766Toeplitz Matrixeasy
• ○867Transpose Matrixeasy
• ○75Sort Colorsmediumamazonmicrosoftmeta
• ○36Valid Sudokumedium
• ○48Rotate Imagemedium
• ○54Spiral Matrixmedium
• ○59Spiral Matrix IImedium
• ○73Set Matrix Zeroesmedium
• ○189Rotate Arraymedium
• ○274H-Indexmedium
• ○289Game of Lifemedium
• ○498Diagonal Traversemedium
• ○135Candyhard

▾Arrays part 2 · 1717

• ○121Best Time to Buy and Sell Stockeasyamazonmetamicrosoftbloomberg
• ○228Summary Rangeseasy
• ○252Meeting Roomspremiumeasy
• ○268Missing Numbereasy
• ○448Find All Numbers Disappeared in an Arrayeasy
• ○53Maximum Subarraymediumamazonmicrosoftbloombergapple
• ○56Merge Intervalsmediumgooglemetaamazonuberbloomberg
• ○57Insert Intervalmedium
• ○152Maximum Product Subarraymedium
• ○253Meeting Rooms IIpremiummedium
• ○287Find the Duplicate Numbermedium
• ○435Non-overlapping Intervalsmedium
• ○918Maximum Sum Circular Subarraymedium
• ○1749Maximum Absolute Sum of Any Subarraymedium
• ○2606Find the Substring With Maximum Costmedium
• ○41First Missing Positivehard
• ○1851Minimum Interval to Include Each Queryhard

▾Arrays part 3 · 1919

• ○26Remove Duplicates from Sorted Arrayeasy
• ○27Remove Elementeasy
• ○88Merge Sorted Arrayeasy
• ○125Valid Palindromeeasy
• ○283Move Zeroeseasy
• ○392Is Subsequenceeasy
• ○153Summediumamazonmetamicrosoftapplebloomberg
• ○11Container With Most Watermediumamazonmetabloomberg
• ○80Remove Duplicates from Sorted Array IImedium
• ○167Two Sum II - Input Array Is Sortedmedium
• ○437Path Sum IIImedium
• ○523Continuous Subarray Summedium
• ○525Contiguous Arraymedium
• ○560Subarray Sum Equals Kmedium
• ○930Binary Subarrays With Summedium
• ○974Subarray Sums Divisible by Kmedium
• ○1248Count Number of Nice Subarraysmedium
• ○42Trapping Rain Waterhardamazongooglemetabloomberg
• ○1074Number of Submatrices That Sum to Targethard

▾Arrays part 4 · 1717

• ○242Valid Anagrameasyamazonmetabloomberg
• ○205Isomorphic Stringseasy
• ○290Word Patterneasy
• ○383Ransom Noteeasy
• ○387First Unique Character in a Stringeasy
• ○49Group Anagramsmediumamazonmetauberbloomberg
• ○437Path Sum IIImedium
• ○438Find All Anagrams in a Stringmedium
• ○451Sort Characters By Frequencymedium
• ○523Continuous Subarray Summedium
• ○525Contiguous Arraymedium
• ○560Subarray Sum Equals Kmedium
• ○930Binary Subarrays With Summedium
• ○974Subarray Sums Divisible by Kmedium
• ○1248Count Number of Nice Subarraysmedium
• ○1657Determine if Two Strings Are Closemedium
• ○1074Number of Submatrices That Sum to Targethard

▾Linked list part 1 · 1111

• ○206Reverse Linked Listeasyamazonmicrosoftapplebloombergmeta
• ○21Merge Two Sorted Listseasyamazonmicrosoftapplebloomberg
• ○83Remove Duplicates from Sorted Listeasy
• ○2Add Two Numbersmedium
• ○19Remove Nth Node From End of Listmedium
• ○24Swap Nodes in Pairsmedium
• ○61Rotate Listmedium
• ○82Remove Duplicates from Sorted List IImedium
• ○86Partition Listmedium
• ○92Reverse Linked List IImedium
• ○25Reverse Nodes in k-Grouphard

▾Linked list part 2 · 1212

• ○141Linked List Cycleeasyamazonmicrosoftbloomberg
• ○202Happy Numbereasy
• ○876Middle of the Linked Listeasy
• ○133Clone Graphmediummetagoogleamazon
• ○138Copy List with Random Pointermediumamazonmicrosoftbloombergapple
• ○143Reorder Listmediumamazonmetabloomberg
• ○142Linked List Cycle IImedium
• ○148Sort Listmedium
• ○287Find the Duplicate Numbermedium
• ○328Odd Even Linked Listmedium
• ○426Convert Binary Search Tree to Sorted Doubly Linked Listpremiummedium
• ○430Flatten a Multilevel Doubly Linked Listmedium

▾Two pointers · 2929

• ○26Remove Duplicates from Sorted Arrayeasy
• ○27Remove Elementeasy
• ○88Merge Sorted Arrayeasy
• ○125Valid Palindromeeasy
• ○219Contains Duplicate IIeasy
• ○283Move Zeroeseasy
• ○392Is Subsequenceeasy
• ○643Maximum Average Subarray Ieasy
• ○3Longest Substring Without Repeating Charactersmediumamazongooglemetamicrosoftbloomberg
• ○153Summediumamazonmetamicrosoftapplebloomberg
• ○11Container With Most Watermediumamazonmetabloomberg
• ○80Remove Duplicates from Sorted Array IImedium
• ○167Two Sum II - Input Array Is Sortedmedium
• ○209Minimum Size Subarray Summedium
• ○340Longest Substring with At Most K Distinct Characterspremiummedium
• ○424Longest Repeating Character Replacementmedium
• ○438Find All Anagrams in a Stringmedium
• ○567Permutation in Stringmedium
• ○904Fruit Into Basketsmedium
• ○1004Max Consecutive Ones IIImedium
• ○1456Maximum Number of Vowels in a Substring of Given Lengthmedium
• ○1493Longest Subarray of 1's After Deleting One Elementmedium
• ○1838Frequency of the Most Frequent Elementmedium
• ○2461Maximum Sum of Distinct Subarrays With Length Kmedium
• ○42Trapping Rain Waterhardamazongooglemetabloomberg
• ○76Minimum Window Substringhardmetaamazongoogleuber
• ○30Substring with Concatenation of All Wordshard
• ○220Contains Duplicate IIIhard
• ○992Subarrays with K Different Integershard

▾Greedy · 1515

• ○252Meeting Roomspremiumeasy
• ○621Task Schedulermediummetaamazonuber
• ○45Jump Game IImedium
• ○55Jump Gamemedium
• ○122Best Time to Buy and Sell Stock IImedium
• ○134Gas Stationmedium
• ○435Non-overlapping Intervalsmedium
• ○452Minimum Number of Arrows to Burst Balloonsmedium
• ○646Maximum Length of Pair Chainmedium
• ○678Valid Parenthesis Stringmedium
• ○763Partition Labelsmedium
• ○846Hand of Straightsmedium
• ○1024Video Stitchingmedium
• ○1306Jump Game IIImedium
• ○1899Merge Triplets to Form Target Tripletmedium

▾Recursion · 1111

• ○17Letter Combinations of a Phone Numbermedium
• ○31Next Permutationmedium
• ○40Combination Sum IImedium
• ○46Permutationsmedium
• ○47Permutations IImedium
• ○77Combinationsmedium
• ○78Subsetsmedium
• ○90Subsets IImedium
• ○556Next Greater Element IIImedium
• ○784Letter Case Permutationmedium
• ○60Permutation Sequencehard

▾Backtracking · 99

• ○22Generate Parenthesesmedium
• ○39Combination Summedium
• ○40Combination Sum IImedium
• ○46Permutationsmedium
• ○77Combinationsmedium
• ○79Word Searchmedium
• ○37Sudoku Solverhard
• ○51N-Queenshard
• ○52N-Queens IIhard

▾Binary search · 1111

• ○35Search Insert Positioneasy
• ○69Sqrt(x)easy
• ○704Binary Searcheasy
• ○33Search in Rotated Sorted Arraymediumamazonmetamicrosoftbloomberg
• ○875Koko Eating Bananasmediumgoogleamazonbytedance
• ○34Find First and Last Position of Element in Sorted Arraymedium
• ○981Time Based Key-Value Storemedium
• ○1011Capacity To Ship Packages Within D Daysmedium
• ○1631Path With Minimum Effortmedium
• ○410Split Array Largest Sumhard
• ○774Minimize Max Distance to Gas Stationpremiumhard

▾Heaps · 1313

• ○1046Last Stone Weighteasy
• ○347Top K Frequent Elementsmediumamazonmetauberbytedance
• ○621Task Schedulermediummetaamazonuber
• ○215Kth Largest Element in an Arraymedium
• ○451Sort Characters By Frequencymedium
• ○973K Closest Points to Originmedium
• ○1962Remove Stones to Minimize the Totalmedium
• ○2542Maximum Subsequence Scoremedium
• ○295Find Median from Data Streamhardamazongooglemetabloomberg
• ○23Merge k Sorted Listshard
• ○480Sliding Window Medianhard
• ○502IPOhard
• ○1851Minimum Interval to Include Each Queryhard

▾Stack and queue part 1 · 1212

• ○20Valid Parentheseseasyamazongooglemetamicrosoftbloomberg
• ○232Implement Queue using Stackseasy
• ○1047Remove All Adjacent Duplicates In Stringeasy
• ○739Daily Temperaturesmediumamazonmetabloomberg
• ○71Simplify Pathmedium
• ○150Evaluate Reverse Polish Notationmedium
• ○227Basic Calculator IImedium
• ○394Decode Stringmedium
• ○678Valid Parenthesis Stringmedium
• ○921Minimum Add to Make Parentheses Validmedium
• ○32Longest Valid Parentheseshard
• ○224Basic Calculatorhard

▾Stack and queue part 2 · 1919

• ○225Implement Stack using Queueseasy
• ○232Implement Queue using Stackseasy
• ○496Next Greater Element Ieasy
• ○739Daily Temperaturesmediumamazonmetabloomberg
• ○155Min Stackmedium
• ○503Next Greater Element IImedium
• ○622Design Circular Queuemedium
• ○641Design Circular Dequemedium
• ○853Car Fleetmedium
• ○907Sum of Subarray Minimumsmedium
• ○1381Design a Stack With Increment Operationmedium
• ○1438Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limitmedium
• ○1696Jump Game VImedium
• ○2762Continuous Subarraysmedium
• ○42Trapping Rain Waterhardamazongooglemetabloomberg
• ○84Largest Rectangle in Histogramhardgoogleamazonbytedance
• ○239Sliding Window Maximumhardamazongooglebytedance
• ○862Shortest Subarray with Sum at Least Khard
• ○1499Max Value of Equationhard

▾Strings part 1 · 2020

• ○242Valid Anagrameasyamazonmetabloomberg
• ○9Palindrome Numbereasy
• ○13Roman to Integereasy
• ○14Longest Common Prefixeasy
• ○58Length of Last Wordeasy
• ○125Valid Palindromeeasy
• ○169Majority Elementeasy
• ○234Palindrome Linked Listeasy
• ○680Valid Palindrome IIeasy
• ○5Longest Palindromic Substringmedium
• ○12Integer to Romanmedium
• ○131Palindrome Partitioningmedium
• ○151Reverse Words in a Stringmedium
• ○271Encode and Decode Stringspremiummedium
• ○274H-Indexmedium
• ○516Longest Palindromic Subsequencemedium
• ○647Palindromic Substringsmedium
• ○132Palindrome Partitioning IIhard
• ○135Candyhard
• ○1312Minimum Insertion Steps to Make a String Palindromehard

▾Strings part 2 · 55

• ○28Find the Index of the First Occurrence in a Stringeasy
• ○438Find All Anagrams in a Stringmedium
• ○686Repeated String Matchmedium
• ○214Shortest Palindromehard
• ○1392Longest Happy Prefixhard

▾Binary tree part 1 · 2222

• ○94Binary Tree Inorder Traversaleasy
• ○101Symmetric Treeeasy
• ○104Maximum Depth of Binary Treeeasy
• ○110Balanced Binary Treeeasy
• ○111Minimum Depth of Binary Treeeasy
• ○222Count Complete Tree Nodeseasy
• ○637Average of Levels in Binary Treeeasy
• ○993Cousins in Binary Treeeasy
• ○102Binary Tree Level Order Traversalmediumamazonmetamicrosoftbytedance
• ○98Validate Binary Search Treemedium
• ○103Binary Tree Zigzag Level Order Traversalmedium
• ○107Binary Tree Level Order Traversal IImedium
• ○116Populating Next Right Pointers in Each Nodemedium
• ○117Populating Next Right Pointers in Each Node IImedium
• ○199Binary Tree Right Side Viewmedium
• ○314Binary Tree Vertical Order Traversalpremiummedium
• ○515Find Largest Value in Each Tree Rowmedium
• ○662Maximum Width of Binary Treemedium
• ○863All Nodes Distance K in Binary Treemedium
• ○958Check Completeness of a Binary Treemedium
• ○1161Maximum Level Sum of a Binary Treemedium
• ○1302Deepest Leaves Summedium

▾Binary tree part 2 · 1717

• ○101Symmetric Treeeasy
• ○111Minimum Depth of Binary Treeeasy
• ○637Average of Levels in Binary Treeeasy
• ○993Cousins in Binary Treeeasy
• ○102Binary Tree Level Order Traversalmediumamazonmetamicrosoftbytedance
• ○103Binary Tree Zigzag Level Order Traversalmedium
• ○107Binary Tree Level Order Traversal IImedium
• ○116Populating Next Right Pointers in Each Nodemedium
• ○117Populating Next Right Pointers in Each Node IImedium
• ○199Binary Tree Right Side Viewmedium
• ○314Binary Tree Vertical Order Traversalpremiummedium
• ○515Find Largest Value in Each Tree Rowmedium
• ○662Maximum Width of Binary Treemedium
• ○863All Nodes Distance K in Binary Treemedium
• ○958Check Completeness of a Binary Treemedium
• ○1161Maximum Level Sum of a Binary Treemedium
• ○1302Deepest Leaves Summedium

▾Binary tree part 3 · 1717

• ○94Binary Tree Inorder Traversaleasy
• ○104Maximum Depth of Binary Treeeasy
• ○110Balanced Binary Treeeasy
• ○112Path Sumeasy
• ○543Diameter of Binary Treeeasy
• ○236Lowest Common Ancestor of a Binary Treemediummetaamazonmicrosoftapple
• ○113Path Sum IImedium
• ○114Flatten Binary Tree to Linked Listmedium
• ○129Sum Root to Leaf Numbersmedium
• ○235Lowest Common Ancestor of a Binary Search Treemedium
• ○437Path Sum IIImedium
• ○865Smallest Subtree with all the Deepest Nodesmedium
• ○1123Lowest Common Ancestor of Deepest Leavesmedium
• ○1448Count Good Nodes in Binary Treemedium
• ○1650Lowest Common Ancestor of a Binary Tree IIIpremiummedium
• ○2096Step-By-Step Directions From a Binary Tree Node to Anothermedium
• ○124Binary Tree Maximum Path Sumhard

▾BST part 1 · 1313

• ○108Convert Sorted Array to Binary Search Treeeasy
• ○501Find Mode in Binary Search Treeeasy
• ○530Minimum Absolute Difference in BSTeasy
• ○700Search in a Binary Search Treeeasy
• ○897Increasing Order Search Treeeasy
• ○98Validate Binary Search Treemedium
• ○173Binary Search Tree Iteratormedium
• ○230Kth Smallest Element in a BSTmedium
• ○235Lowest Common Ancestor of a Binary Search Treemedium
• ○450Delete Node in a BSTmedium
• ○538Convert BST to Greater Treemedium
• ○701Insert into a Binary Search Treemedium
• ○99Recover Binary Search Treehard

▾BST part 2 · 2020

• ○100Same Treeeasy
• ○101Symmetric Treeeasy
• ○108Convert Sorted Array to Binary Search Treeeasy
• ○501Find Mode in Binary Search Treeeasy
• ○530Minimum Absolute Difference in BSTeasy
• ○572Subtree of Another Treeeasy
• ○617Merge Two Binary Treeseasy
• ○700Search in a Binary Search Treeeasy
• ○897Increasing Order Search Treeeasy
• ○98Validate Binary Search Treemedium
• ○173Binary Search Tree Iteratormedium
• ○230Kth Smallest Element in a BSTmedium
• ○235Lowest Common Ancestor of a Binary Search Treemedium
• ○449Serialize and Deserialize BSTmedium
• ○450Delete Node in a BSTmedium
• ○538Convert BST to Greater Treemedium
• ○652Find Duplicate Subtreesmedium
• ○701Insert into a Binary Search Treemedium
• ○297Serialize and Deserialize Binary Treehardmetaamazongooglebloomberg
• ○99Recover Binary Search Treehard

▾Mixed trees · 1212

• ○100Same Treeeasy
• ○101Symmetric Treeeasy
• ○572Subtree of Another Treeeasy
• ○617Merge Two Binary Treeseasy
• ○105Construct Binary Tree from Preorder and Inorder Traversalmedium
• ○106Construct Binary Tree from Inorder and Postorder Traversalmedium
• ○449Serialize and Deserialize BSTmedium
• ○652Find Duplicate Subtreesmedium
• ○654Maximum Binary Treemedium
• ○889Construct Binary Tree from Preorder and Postorder Traversalmedium
• ○1008Construct Binary Search Tree from Preorder Traversalmedium
• ○297Serialize and Deserialize Binary Treehardmetaamazongooglebloomberg

▾Graph part 1 · 1212

• ○112Path Sumeasy
• ○200Number of Islandsmediumamazongooglemetamicrosoftbytedance
• ○102Binary Tree Level Order Traversalmediumamazonmetamicrosoftbytedance
• ○207Course Schedulemediumgoogleamazonmetabytedance
• ○133Clone Graphmediummetagoogleamazon
• ○994Rotting Orangesmediumamazonmicrosoftbytedance
• ○433Minimum Genetic Mutationmedium
• ○695Max Area of Islandmedium
• ○909Snakes and Laddersmedium
• ○1091Shortest Path in Binary Matrixmedium
• ○127Word Ladderhardamazongooglebytedance
• ○1293Shortest Path in a Grid with Obstacles Eliminationhard

▾Graph part 2 · 1313

• ○207Course Schedulemediumgoogleamazonmetabytedance
• ○743Network Delay Timemediumgoogleuberamazon
• ○787Cheapest Flights Within K Stopsmediumgoogleuberamazon
• ○1584Min Cost to Connect All Pointsmediumamazonuber
• ○210Course Schedule IImedium
• ○310Minimum Height Treesmedium
• ○1135Connecting Cities With Minimum Costpremiummedium
• ○1136Parallel Coursespremiummedium
• ○1334Find the City With the Smallest Number of Neighbors at a Threshold Distancemedium
• ○1631Path With Minimum Effortmedium
• ○269Alien Dictionarypremiumhardgooglemetaamazon
• ○778Swim in Rising Waterhard
• ○1168Optimize Water Distribution in a Villagepremiumhard

▾DP part 1 · 1313

• ○70Climbing Stairseasy
• ○118Pascal's Triangleeasy
• ○509Fibonacci Numbereasy
• ○746Min Cost Climbing Stairseasy
• ○1137N-th Tribonacci Numbereasy
• ○139Word Breakmediumgoogleamazonmetabytedance
• ○300Longest Increasing Subsequencemediumgooglemicrosoftbytedanceuber
• ○322Coin Changemediumamazongooglemicrosoftbytedance
• ○91Decode Waysmedium
• ○198House Robbermedium
• ○213House Robber IImedium
• ○518Coin Change IImedium
• ○1824Minimum Sideway Jumpsmedium

▾DP part 2 · 1515

• ○72Edit Distancemediumgoogleamazonmicrosoftbytedance
• ○300Longest Increasing Subsequencemediumgooglemicrosoftbytedanceuber
• ○1143Longest Common Subsequencemediumgoogleamazonmicrosoft
• ○97Interleaving Stringmedium
• ○309Best Time to Buy and Sell Stock with Cooldownmedium
• ○416Partition Equal Subset Summedium
• ○474Ones and Zeroesmedium
• ○494Target Summedium
• ○516Longest Palindromic Subsequencemedium
• ○583Delete Operation for Two Stringsmedium
• ○1049Last Stone Weight IImedium
• ○10Regular Expression Matchinghard
• ○115Distinct Subsequenceshard
• ○123Best Time to Buy and Sell Stock IIIhard
• ○188Best Time to Buy and Sell Stock IVhard

▾Tries · 88

• ○208Implement Trie (Prefix Tree)mediumgoogleamazonbloomberg
• ○211Design Add and Search Words Data Structuremedium
• ○421Maximum XOR of Two Numbers in an Arraymedium
• ○648Replace Wordsmedium
• ○677Map Sum Pairsmedium
• ○720Longest Word in Dictionarymedium
• ○1268Search Suggestions Systemmedium
• ○212Word Search IIhardgoogleamazonbytedance

Before you start this sheet

Do the consensus problems first. They are the problems every sheet author independently agreed on, so they are the highest-value problems available regardless of which sheet you eventually commit to.