| 1 | | |
| Course Roadmap | |
| Join the Community | |
| 2 | | |
| Introduction | |
| Best, Worst, and Average Complexity | |
| Amortized Analysis | |
| Recurrence Relations | |
| Master Theorem | |
| 3 | | |
| Introduction | |
| Move Zeroes | Easy |
| Majority Element | Easy |
| Remove Duplicates from Sorted Array | Easy |
| Best Time to Buy and Sell Stock | Easy |
| Rotate Array | Medium |
| Product of Array Except Self | Medium |
| Best Time to Buy and Sell Stock II | Medium |
| Number of Zero-Filled Subarrays | Medium |
| Increasing Triplet Subsequence | Medium |
| First Missing Positive | Hard |
| 4 | | |
| Is Subsequence | Easy |
| Valid Palindrome | Easy |
| Longest Common Prefix | Easy |
| Zigzag Conversion | Medium |
| Reverse Words in a String | Medium |
| Guess the Word | Hard |
| 5 | | |
| Introduction | |
| Single Number | Easy |
| Number of 1 Bits | Easy |
| Counting Bits | Easy |
| Reverse Bits | Easy |
| Bitwise AND of Numbers Range | Medium |
| Single Number III | Medium |
| Sum of Two Integers | Medium |
| 6 | | |
| Introduction | |
| Design HashMap | Easy |
| Maximum Number of Balloons | Easy |
| Number of Good Pairs | Easy |
| Isomorphic Strings | Easy |
| Ransom Note | Easy |
| Contains Duplicate II | Easy |
| Group Anagrams | Medium |
| Encode and Decode TinyURL | Medium |
| Reorganize String | Medium |
| Longest Consecutive Sequence | Medium |
| Split Array into Consecutive Subsequences | Medium |
| Number of Matching Subsequences | Medium |
| Number of Good Ways to Split a String | Medium |
| 7 | | |
| Introduction | |
| Merge Sorted Array | Easy |
| Two Sum II - Input Array Is Sorted | Medium |
| Container With Most Water | Medium |
| 3Sum | Medium |
| Trapping Rain Water | Hard |
| 8 | | |
| Introduction | |
| Range Sum Query - Immutable | Easy |
| Subarray Sum Equals K | Medium |
| Subarray Sums Divisible by K | Medium |
| Continuous Subarray Sum | Medium |
| Contiguous Array | Medium |
| 9 | | |
| Introduction | |
| Fixed Size | |
| Maximum Average Subarray I | Easy |
| Find All Anagrams in a String | Medium |
| Permutation in String | Medium |
| Maximum Sum of Distinct Subarrays With Length K | Medium |
| Substring with Concatenation of All Words | Hard |
| Dynamic Size | |
| Longest Substring Without Repeating Characters | Medium |
| Longest Repeating Character Replacement | Medium |
| Minimum Size Subarray Sum | Medium |
| Max Consecutive Ones III | Medium |
| Minimum Window Substring | Hard |
| 10 | | |
| Introduction | |
| Maximum Subarray | Medium |
| Maximum Sum Circular Subarray | Medium |
| Maximum Product Subarray | Medium |
| Best Sightseeing Pair | Medium |
| 11 | | |
| Spiral Matrix | Medium |
| Rotate Image | Medium |
| Set Matrix Zeroes | Medium |
| Valid Sudoku | Medium |
| Game of Life | Medium |
| 12 | | |
| Introduction | |
| Intersection of Two Linked Lists | Easy |
| Design Linked List | Medium |
| Remove Nth Node From End of List | Medium |
| Remove Duplicates from Sorted List II | Medium |
| Swap Nodes in Pairs | Medium |
| Copy List with Random Pointer | Medium |
| Partition List | Medium |
| Rotate List | Medium |
| Add Two Numbers | Medium |
| Flatten a Multilevel Doubly Linked List | Medium |
| In-place Reversal | |
| Introduction | |
| Palindrome Linked List | Easy |
| Reverse Linked List | Easy |
| Reverse Linked List II | Medium |
| Reverse Nodes in k-Group | Hard |
| Fast and Slow Pointers | |
| Introduction | |
| Middle of the Linked List | Easy |
| Happy Number | Easy |
| Linked List Cycle II | Medium |
| 13 | | |
| Introduction | |
| Valid Parentheses | Easy |
| Remove All Adjacent Duplicates In String | Easy |
| Min Stack | Medium |
| Remove Duplicate Letters | Medium |
| Removing Stars From a String | Medium |
| Evaluate Reverse Polish Notation | Medium |
| Basic Calculator II | Medium |
| Longest Valid Parentheses | Hard |
| Monotonic Stack | |
| Introduction | |
| Next Greater Element I | Easy |
| Daily Temperatures | Medium |
| Online Stock Span | Medium |
| 132 Pattern | Medium |
| Number of Visible People in a Queue | Hard |
| Largest Rectangle in Histogram | Hard |
| 14 | | |
| Introduction | |
| Number of Recent Calls | Easy |
| Time Needed to Buy Tickets | Easy |
| Reveal Cards In Increasing Order | Medium |
| Monotonic Queue | |
| Jump Game VI | Medium |
| Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit | Medium |
| Sliding Window Maximum | Hard |
| Max Value of Equation | Hard |
| 15 | | |
| Bucket Sort | |
| Sort Characters By Frequency | Medium |
| Top K Frequent Words | Medium |
| Maximum Gap | Medium |
| Merge Sort | |
| Sort List | Medium |
| Reverse Pairs | Hard |
| Quick Sort / QuickSelect | |
| Sort Colors | Medium |
| Kth Largest Element in an Array | Medium |
| 16 | | |
| Introduction to Backtracking | |
| Merge Two Sorted Lists | Easy |
| Pow(x, n) | Medium |
| Decode String | Medium |
| Generate Parentheses | Medium |
| Permutations | Medium |
| Subsets | Medium |
| Combination Sum | Medium |
| Combination Sum II | Medium |
| Letter Combinations of a Phone Number | Medium |
| Palindrome Partitioning | Medium |
| N-Queens | Hard |
| 17 | | |
| Convert Sorted List to Binary Search Tree | Medium |
| Construct Quad Tree | Medium |
| Maximum Binary Tree | Medium |
| 18 | | |
| Introduction | |
| Search Insert Position | Easy |
| Find First and Last Position of Element in Sorted Array | Medium |
| Search in Rotated Sorted Array | Medium |
| Find Peak Element | Medium |
| Random Pick with Weight | Medium |
| Koko Eating Bananas | Medium |
| Find Minimum in Rotated Sorted Array | Medium |
| Search a 2D Matrix | Medium |
| Find in Mountain Array | Hard |
| Median of Two Sorted Arrays | Hard |
| 19 | | |
| Introduction | |
| Level Order | |
| Binary Tree Level Order Traversal | Medium |
| Binary Tree Right Side View | Medium |
| Binary Tree Zigzag Level Order Traversal | Medium |
| Populating Next Right Pointers in Each Node II | Medium |
| Maximum Width of Binary Tree | Medium |
| Pre Order | |
| Binary Tree Preorder Traversal | Easy |
| Same Tree | Easy |
| Symmetric Tree | Easy |
| Binary Tree Paths | Easy |
| Convert Sorted Array to Binary Search Tree | Easy |
| Count Complete Tree Nodes | Easy |
| Path Sum III | Medium |
| Maximum Difference Between Node and Ancestor | Medium |
| Construct Binary Tree from Preorder and Inorder Traversal | Medium |
| Construct Binary Tree from Inorder and Postorder Traversal | Medium |
| Serialize and Deserialize Binary Tree | Hard |
| In Order | |
| Binary Tree Inorder Traversal | Easy |
| Minimum Distance Between BST Nodes | Easy |
| Minimum Absolute Difference in BST | Easy |
| Validate Binary Search Tree | Medium |
| Kth Smallest Element in a BST | Medium |
| Binary Search Tree Iterator | Medium |
| Post Order | |
| Binary Tree Postorder Traversal | Easy |
| Invert Binary Tree | Easy |
| Diameter of Binary Tree | Easy |
| Delete Nodes And Return Forest | Medium |
| Lowest Common Ancestor of a Binary Tree | Medium |
| Find Duplicate Subtrees | Medium |
| Flatten Binary Tree to Linked List | Medium |
| Distribute Coins in Binary Tree | Medium |
| Binary Tree Maximum Path Sum | Hard |
| 20 | | |
| Introduction | |
| Trim a Binary Search Tree | Medium |
| My Calendar I | Medium |
| My Calendar II | Medium |
| Stock Price Fluctuation | Medium |
| 21 | | |
| Introduction | |
| Implement Trie (Prefix Tree) | Medium |
| Design Add and Search Words Data Structure | Medium |
| Search Suggestions System | Medium |
| Longest Word in Dictionary | Medium |
| Maximum XOR of Two Numbers in an Array | Medium |
| Word Search II | Hard |
| 22 | | |
| Introduction | |
| Furthest Building You Can Reach | Medium |
| Single-Threaded CPU | Medium |
| Process Tasks Using Servers | Medium |
| Two Heaps | |
| Find Median from Data Stream | Hard |
| IPO | Hard |
| Sliding Window Median | Hard |
| K-Way Merge | |
| Find K Pairs with Smallest Sums | Medium |
| Kth Smallest Element in a Sorted Matrix | Medium |
| Merge k Sorted Lists | Hard |
| Smallest Range Covering Elements from K Lists | Hard |
| Top K Elements | |
| Introduction | |
| Kth Largest Element in a Stream | Easy |
| Top K Frequent Elements | Medium |
| K Closest Points to Origin | Medium |
| 23 | | |
| Introduction to Intervals | |
| Merge Intervals | Medium |
| Insert Interval | Medium |
| Minimum Number of Arrows to Burst Balloons | Medium |
| Maximum Number of Events That Can Be Attended | Medium |
| Non-overlapping Intervals | Medium |
| 24 | | |
| Design Browser History | Medium |
| Time Based Key-Value Store | Medium |
| Snapshot Array | Medium |
| Design Twitter | Medium |
| LRU Cache | Medium |
| Insert Delete GetRandom O(1) | Medium |
| Design a Food Rating System | Medium |
| Maximum Frequency Stack | Hard |
| 25 | | |
| Introduction | |
| Jump Game II | Medium |
| Minimum Add to Make Parentheses Valid | Medium |
| Gas Station | Medium |
| Task Scheduler | Medium |
| Minimum Cost to Hire K Workers | Hard |
| Candy | Hard |
| Minimum Number of Refueling Stops | Hard |
| 26 | | |
| Introduction | |
| Matrix Traversal | |
| Depth-First Search | |
| Introduction | |
| Number of Islands | Medium |
| Time Needed to Inform All Employees | Medium |
| All Paths From Source to Target | Medium |
| Clone Graph | Medium |
| Is Graph Bipartite? | Medium |
| All Nodes Distance K in Binary Tree | Medium |
| Employee Importance | Medium |
| Surrounded Regions | Medium |
| Pacific Atlantic Water Flow | Medium |
| Making A Large Island | Hard |
| Breadth-First Search | |
| Introduction | |
| Rotting Oranges | Medium |
| 01 Matrix | Medium |
| Open the Lock | Medium |
| Shortest Path in a Grid with Obstacles Elimination | Hard |
| Bus Routes | Hard |
| Word Ladder | Hard |
| Topological Sort | |
| Introduction | |
| Course Schedule II | Medium |
| Find Eventual Safe States | Medium |
| Minimum Height Trees | Medium |
| Sort Items by Groups Respecting Dependencies | Hard |
| Union Find | |
| Introduction | |
| Number of Provinces | Medium |
| Redundant Connection | Medium |
| Accounts Merge | Medium |
| Minimize Malware Spread | Hard |
| Union Find | |
| Min Cost to Connect All Points | Medium |
| Shortest Path | |
| Introduction | |
| Network Delay Time | Medium |
| Cheapest Flights Within K Stops | Medium |
| Path with Maximum Probability | Medium |
| Path With Minimum Effort | Medium |
| Swim in Rising Water | Hard |
| Eulerian Circuit | |
| Reconstruct Itinerary | Hard |
| Cracking the Safe | Hard |
| 27 | | |
| 1-D DP | |
| Climbing Stairs | Easy |
| Min Cost Climbing Stairs | Easy |
| House Robber | Medium |
| House Robber II | Medium |
| Knapsack | |
| Partition Equal Subset Sum | Medium |
| Target Sum | Medium |
| Last Stone Weight II | Medium |
| Unbounded Knapsack | |
| Coin Change | Medium |
| Coin Change II | Medium |
| Perfect Squares | Medium |
| LIS | |
| Longest Increasing Subsequence | Medium |
| Number of Longest Increasing Subsequence | Medium |
| Russian Doll Envelopes | Hard |
| 2D (Grid) DP | |
| Unique Paths II | Medium |
| Minimum Path Sum | Medium |
| Triangle | Medium |
| Count Square Submatrices with All Ones | Medium |
| Maximum Number of Points with Cost | Medium |
| Burst Balloons | Hard |
| Maximum Profit in Job Scheduling | Hard |
| Cherry Pickup | Hard |
| Longest Increasing Path in a Matrix | Hard |
| String DP | |
| Longest Common Subsequence | Medium |
| Edit Distance | Medium |
| Longest Palindromic Subsequence | Medium |
| Decode Ways | Medium |
| Word Break | Medium |
| Interleaving String | Medium |
| Wildcard Matching | Hard |
| Distinct Subsequences | Hard |
| Palindrome Partitioning II | Hard |
| Tree / Graph DP | |
| House Robber III | Medium |
| Unique Binary Search Trees II | Medium |
| Number of Ways to Arrive at Destination | Medium |
| Binary Tree Cameras | Hard |
| Sum of Distances in Tree | Hard |
| Bitmask DP | |
| Minimum Number of Work Sessions to Finish the Tasks | Medium |
| Fair Distribution of Cookies | Medium |
| Shortest Path Visiting All Nodes | Hard |
| Digit DP | |
| Count Numbers with Unique Digits | Medium |
| Number of Digit One | Hard |
| Numbers At Most N Given Digit Set | Hard |
| Probability DP | |
| Knight Probability in Chessboard | Medium |
| Soup Servings | Medium |
| New 21 Game | Medium |
| State Machine DP | |
| Best Time to Buy and Sell Stock with Cooldown | Medium |
| Best Time to Buy and Sell Stock III | Hard |
| 28 | | |
| Palindrome Number | Easy |
| Reverse Integer | Medium |
| Factorial Trailing Zeroes | Medium |
| Valid Square | Medium |
| Minimum Area Rectangle II | Medium |
| Max Points on a Line | Hard |
| 29 | | |
| String Matching | |
| Repeated String Match | Medium |
| Shortest Palindrome | Hard |
| Segment Tree | |
| Range Sum Query - Mutable | Medium |
| Count of Smaller Numbers After Self | Hard |
| Line Sweep | |
| Minimum Interval to Include Each Query | Hard |
| The Skyline Problem | Hard |
| Line SweepSuffix Array | |
| Longest Duplicate Substring | Hard |
