Snap LeetCode Questions
84 questions all-time · 5 easy · 52 medium · 27 hard
| # | Problem | Difficulty | Frequency | Acceptance |
|---|---|---|---|---|
| 1 | LRU Cache Hash Table, Linked List, Design, Doubly-Linked List | Medium | 100 | 0.5% |
| 2 | Meeting Rooms II Array, Two Pointers, Greedy, Sorting, Heap (Priority Queue), Prefix Sum | Medium | 96 | 0.5% |
| 3 | Number of Islands Array, Depth-First Search, Breadth-First Search, Union-Find, Matrix | Medium | 94 | 0.6% |
| 4 | Minimum Window Substring Hash Table, String, Sliding Window | Hard | 93 | 0.5% |
| 5 | Word Ladder Hash Table, String, Breadth-First Search | Hard | 93 | 0.5% |
| 6 | Design Log Storage System Hash Table, String, Design, Ordered Set | Medium | 91 | 0.6% |
| 7 | Making A Large Island Array, Depth-First Search, Breadth-First Search, Union-Find, Matrix | Hard | 89 | 0.6% |
| 8 | Number of Distinct Islands Array, Hash Table, Depth-First Search, Breadth-First Search, Union-Find, Sorting, Matrix, Hash Function | Medium | 89 | 0.6% |
| 9 | Word Break II Array, Hash Table, String, Dynamic Programming, Backtracking, Trie, Memoization | Hard | 87 | 0.6% |
| 10 | Bus Routes Array, Hash Table, Breadth-First Search | Hard | 87 | 0.5% |
| 11 | Combination Sum Array, Backtracking | Medium | 85 | 0.8% |
| 12 | Reverse Words in a String Two Pointers, String | Medium | 85 | 0.6% |
| 13 | Basic Calculator II Math, String, Stack | Medium | 85 | 0.5% |
| 14 | Valid Sudoku Array, Hash Table, Matrix | Medium | 83 | 0.6% |
| 15 | Sudoku Solver Array, Hash Table, Backtracking, Matrix | Hard | 83 | 0.7% |
| 16 | Combination Sum II Array, Backtracking | Medium | 83 | 0.6% |
| 17 | Wildcard Matching String, Dynamic Programming, Greedy, Recursion | Hard | 83 | 0.3% |
| 18 | Unique Binary Search Trees Math, Dynamic Programming, Tree, Binary Search Tree, Binary Tree | Medium | 83 | 0.6% |
| 19 | Min Stack Stack, Design | Medium | 83 | 0.6% |
| 20 | One Edit Distance Two Pointers, String | Medium | 83 | 0.3% |
| 21 | Reverse Linked List Linked List, Recursion | Easy | 83 | 0.8% |
| 22 | Alien Dictionary Array, String, Depth-First Search, Breadth-First Search, Graph Theory, Topological Sort | Hard | 83 | 0.4% |
| 23 | Closest Binary Search Tree Value Binary Search, Tree, Depth-First Search, Binary Search Tree, Binary Tree | Easy | 83 | 0.5% |
| 24 | Game of Life Array, Matrix, Simulation | Medium | 83 | 0.7% |
| 25 | Burst Balloons Array, Dynamic Programming | Hard | 83 | 0.6% |
| 26 | Binary Tree Vertical Order Traversal Hash Table, Tree, Depth-First Search, Breadth-First Search, Sorting, Binary Tree | Medium | 83 | 0.6% |
| 27 | Combination Sum IV Array, Dynamic Programming | Medium | 83 | 0.6% |
| 28 | Remove K Digits String, Stack, Greedy, Monotonic Stack | Medium | 83 | 0.4% |
| 29 | Frog Jump Array, Dynamic Programming | Hard | 83 | 0.5% |
| 30 | Ternary Expression Parser String, Stack, Recursion | Medium | 83 | 0.6% |
| 31 | String Compression Two Pointers, String | Medium | 83 | 0.6% |
| 32 | Word Abbreviation Array, String, Greedy, Trie, Sorting | Hard | 83 | 0.6% |
| 33 | Largest Merge Of Two Strings Two Pointers, String, Greedy | Medium | 83 | 0.5% |
| 34 | Least Operators to Express Number Math, Dynamic Programming, Memoization | Hard | 83 | 0.5% |
| 35 | Bricks Falling When Hit Array, Union-Find, Matrix | Hard | 83 | 0.4% |
| 36 | Course Schedule II Depth-First Search, Breadth-First Search, Graph Theory, Topological Sort | Medium | 77 | 0.6% |
| 37 | Top K Frequent Elements Array, Hash Table, Divide and Conquer, Sorting, Heap (Priority Queue), Bucket Sort, Counting, Quickselect | Medium | 77 | 0.7% |
| 38 | Best Time to Buy and Sell Stock III Array, Dynamic Programming | Hard | 66 | 0.5% |
| 39 | Decode Ways String, Dynamic Programming | Medium | 66 | 0.4% |
| 40 | Best Meeting Point Array, Math, Sorting, Matrix | Hard | 66 | 0.6% |
| 41 | Evaluate Division Array, String, Depth-First Search, Breadth-First Search, Union-Find, Graph Theory, Shortest Path | Medium | 60 | 0.6% |
| 42 | Basic Calculator III Math, String, Stack, Recursion | Hard | 60 | 0.5% |
| 43 | Count Unreachable Pairs of Nodes in an Undirected Graph Depth-First Search, Breadth-First Search, Union-Find, Graph Theory | Medium | 60 | 0.5% |
| 44 | Escape the Spreading Fire Array, Binary Search, Breadth-First Search, Matrix | Hard | 60 | 0.4% |
| 45 | Merge Intervals Array, Sorting | Medium | 53 | 0.5% |
| 46 | Course Schedule Depth-First Search, Breadth-First Search, Graph Theory, Topological Sort | Medium | 53 | 0.5% |
| 47 | Power of Two Math, Bit Manipulation, Recursion | Easy | 53 | 0.5% |
| 48 | Minimum Remove to Make Valid Parentheses String, Stack | Medium | 53 | 0.7% |
| 49 | Shortest Path in a Grid with Obstacles Elimination Array, Breadth-First Search, Matrix | Hard | 53 | 0.5% |
| 50 | Group Anagrams Array, Hash Table, String, Sorting | Medium | 53 | 0.7% |
| 51 | Minimum Area Rectangle Array, Hash Table, Math, Geometry, Sorting | Medium | 53 | 0.6% |
| 52 | Reorder List Linked List, Two Pointers, Stack, Recursion | Medium | 53 | 0.7% |
| 53 | Word Search II Array, String, Backtracking, Trie, Matrix | Hard | 53 | 0.4% |
| 54 | LFU Cache Hash Table, Linked List, Design, Doubly-Linked List | Hard | 53 | 0.5% |
| 55 | Reaching Points Math | Hard | 53 | 0.3% |
| 56 | Basic Calculator Math, String, Stack, Recursion | Hard | 53 | 0.5% |
| 57 | Open the Lock Array, Hash Table, String, Breadth-First Search | Medium | 53 | 0.6% |
| 58 | Word Search Array, String, Backtracking, Depth-First Search, Matrix | Medium | 43 | 0.5% |
| 59 | Binary Tree Maximum Path Sum Dynamic Programming, Tree, Depth-First Search, Binary Tree | Hard | 43 | 0.4% |
| 60 | Cheapest Flights Within K Stops Dynamic Programming, Depth-First Search, Breadth-First Search, Graph Theory, Heap (Priority Queue), Shortest Path | Medium | 43 | 0.4% |
| 61 | Random Pick with Weight Array, Math, Binary Search, Prefix Sum, Randomized | Medium | 43 | 0.5% |
| 62 | Design Browser History Array, Linked List, Stack, Design, Doubly-Linked List, Data Stream | Medium | 43 | 0.8% |
| 63 | K Closest Points to Origin Array, Math, Divide and Conquer, Geometry, Sorting, Heap (Priority Queue), Quickselect | Medium | 43 | 0.7% |
| 64 | The Maze Array, Depth-First Search, Breadth-First Search, Matrix | Medium | 43 | 0.6% |
| 65 | Product of Array Except Self Array, Prefix Sum | Medium | 43 | 0.7% |
| 66 | Search in Rotated Sorted Array Array, Binary Search | Medium | 43 | 0.5% |
| 67 | Shortest Path in Binary Matrix Array, Breadth-First Search, Matrix | Medium | 43 | 0.5% |
| 68 | Minimum Number of Pushes to Type Word I Math, String, Greedy | Easy | 43 | 0.7% |
| 69 | Letter Combinations of a Phone Number Hash Table, String, Backtracking | Medium | 43 | 0.7% |
| 70 | Snapshot Array Array, Hash Table, Binary Search, Design | Medium | 43 | 0.4% |
| 71 | Add Binary Math, String, Bit Manipulation, Simulation | Easy | 43 | 0.6% |
| 72 | Number of Ways to Form a Target String Given a Dictionary Array, String, Dynamic Programming | Hard | 43 | 0.6% |
| 73 | Design Add and Search Words Data Structure String, Depth-First Search, Design, Trie | Medium | 43 | 0.5% |
| 74 | Longest Substring Without Repeating Characters Hash Table, String, Sliding Window | Medium | 43 | 0.4% |
| 75 | Minimum Path Sum Array, Dynamic Programming, Matrix | Medium | 43 | 0.7% |
| 76 | Number of Submatrices That Sum to Target Array, Hash Table, Matrix, Prefix Sum | Hard | 43 | 0.7% |
| 77 | UTF-8 Validation Array, Bit Manipulation | Medium | 43 | 0.5% |
| 78 | Koko Eating Bananas Array, Binary Search | Medium | 43 | 0.5% |
| 79 | Sliding Window Median Array, Hash Table, Sliding Window, Heap (Priority Queue) | Hard | 43 | 0.4% |
| 80 | Possible Bipartition Depth-First Search, Breadth-First Search, Union-Find, Graph Theory | Medium | 43 | 0.5% |
| 81 | Most Stones Removed with Same Row or Column Hash Table, Depth-First Search, Union-Find, Graph Theory | Medium | 43 | 0.6% |
| 82 | Fraction to Recurring Decimal Hash Table, Math, String | Medium | 43 | 0.3% |
| 83 | Design Hit Counter Array, Binary Search, Design, Queue, Data Stream | Medium | 43 | 0.7% |
| 84 | Merge k Sorted Lists Linked List, Divide and Conquer, Heap (Priority Queue), Merge Sort | Hard | 43 | 0.6% |
How to read this list
The tabs at the top split the questions by how recently people said they were asked in interviews. "Last 30 Days" is the past month, "Last 3 Months" is the past quarter, and so on. "All Time" is every question on record for this company.
Frequency is a score from 0 to 100 for how often a question showed up in that time window. A higher number means it came up more often, so the list starts with the most common questions first. Acceptance is the share of submissions that pass on LeetCode. Click any question to open it on LeetCode.