1 Longest Palindromic Substring Two Pointers String Dynamic Programming
Medium 100
35.8% 2 Predict the Winner Array Math Dynamic Programming Recursion Game Theory
Medium 98
55.7% 3 House Robber Array Dynamic Programming
Medium 98
52.3% 4 Lucky Numbers in a Matrix Array Matrix
Easy 85
79.9% 5 Rotate Image Array Math Matrix
Medium 85
77.9% 6 Spiral Matrix Array Matrix Simulation
Medium 84
53.9% 7 Fizz Buzz Math String Simulation
Easy 70
74.4% 8 LRU Cache Hash Table Linked List Design Doubly-Linked List
Medium 67
45.2% 9 Snakes and Ladders Array Breadth-First Search Matrix
Medium 67
47.8% 10 Number of Valid Words in a Sentence String
Easy 67
30.0% 11 Find Third Transaction Database
Medium 65
53.9% 12 Maximum Difference Between Increasing Elements Array
Easy 65
66.1% 13 Merge Intervals Array Sorting
Medium 65
49.4% 14 Maximum Subarray Array Divide and Conquer Dynamic Programming
Medium 63
52.1% 15 Implement Router Array Hash Table Binary Search Design Queue Ordered Set
Medium 63
21.8% 16 Find the Largest Area of Square Inside Two Rectangles Array Math Geometry
Medium 63
45.1% 17 Minimum Cost to Make Array Equal Array Binary Search Greedy Sorting Prefix Sum
Hard 63
46.3% 18 Word Search II Array String Backtracking Trie Matrix
Hard 63
37.3% 19 Number of Equal Count Substrings Hash Table String Sliding Window Counting
Medium 63
44.7% 20 Sum of k-Mirror Numbers Math Enumeration
Hard 63
42.0% 21 Check if Binary String Has at Most One Segment of Ones String
Easy 63
39.0% 22 Max Points on a Line Array Hash Table Math Geometry
Hard 59
29.0% 23 Happy Number Hash Table Math Two Pointers
Easy 59
58.1% 24 Stone Game Array Math Dynamic Programming Game Theory
Medium 59
71.6% 25 Two Sum Array Hash Table
Easy 59
55.8% 26 Cherry Pickup Array Dynamic Programming Matrix
Hard 56
37.9% 27 Valid Parentheses String Stack
Easy 56
42.3% 28 Trapping Rain Water Array Two Pointers Dynamic Programming Stack Monotonic Stack
Hard 56
65.1% 29 Longest Substring Without Repeating Characters Hash Table String Sliding Window
Medium 53
36.9% 30 Linked List Cycle Hash Table Linked List Two Pointers
Easy 50
52.6% 31 Decode String String Stack Recursion
Medium 50
61.2% 32 Best Time to Buy and Sell Stock Array Dynamic Programming
Easy 50
55.3% 33 Remove Boxes Array Dynamic Programming Memoization
Hard 50
48.3% 34 Merge Sorted Array Array Two Pointers Sorting
Easy 50
52.9% 35 Strange Printer String Dynamic Programming
Hard 45
60.8% 36 Longest Consecutive Sequence Array Hash Table Union Find
Medium 45
47.0% 37 Letter Combinations of a Phone Number Hash Table String Backtracking
Medium 45
63.9% 38 Move Zeroes Array Two Pointers
Easy 45
62.8% 39 3Sum Array Two Pointers Sorting
Medium 45
37.1% 40 Reverse Linked List Linked List Recursion
Easy 45
79.2% 41 Number of Islands Array Depth-First Search Breadth-First Search Union Find Matrix
Medium 45
62.3% 42 Search a 2D Matrix Array Binary Search Matrix
Medium 45
52.3% 43 Word Search Array String Backtracking Depth-First Search Matrix
Medium 40
45.3% 44 Gas Station Array Greedy
Medium 40
46.4% 45 Remove Duplicates from Sorted Array Array Two Pointers
Easy 40
60.4% 46 Meeting Rooms II Array Two Pointers Greedy Sorting Heap (Priority Queue) Prefix Sum
Medium 40
52.1% 47 Valid Palindrome Two Pointers String
Easy 40
51.0% 48 Permutation in String Hash Table Two Pointers String Sliding Window
Medium 40
47.2% 49 Merge k Sorted Lists Linked List Divide and Conquer Heap (Priority Queue) Merge Sort
Hard 40
56.8% 50 Group Anagrams Array Hash Table String Sorting
Medium 40
70.9% 51 Single Number Array Bit Manipulation
Easy 40
76.0% 52 Find Servers That Handled Most Number of Requests Array Greedy Heap (Priority Queue) Ordered Set
Hard 40
44.1% 53 Insert Delete GetRandom O(1) Array Hash Table Math Design Randomized
Medium 40
55.0% 54 Validate IP Address String
Medium 40
27.8% 55 Top K Frequent Elements Array Hash Table Divide and Conquer Sorting Heap (Priority Queue) Bucket Sort Counting Quickselect
Medium 40
64.6% 56 Add Two Numbers Linked List Math Recursion
Medium 40
46.2% 57 Expressive Words Array Two Pointers String
Medium 40
46.4% 58 Edit Distance String Dynamic Programming
Medium 32
58.8% 59 Subarray Sum Equals K Array Hash Table Prefix Sum
Medium 32
45.5% 60 Rising Temperature Database
Easy 32
50.2% 61 Can Place Flowers Array Greedy
Easy 32
28.9% 62 Kth Smallest Element in a BST Tree Depth-First Search Binary Search Tree Binary Tree
Medium 32
75.3% 63 Missing Number Array Hash Table Math Binary Search Bit Manipulation Sorting
Easy 32
70.1% 64 Find Minimum in Rotated Sorted Array Array Binary Search
Medium 32
52.6% 65 Unique Paths Math Dynamic Programming Combinatorics
Medium 32
65.8% 66 Zigzag Conversion String
Medium 32
51.6% 67 Permutations Array Backtracking
Medium 32
80.7% 68 Sliding Window Maximum Array Queue Sliding Window Heap (Priority Queue) Monotonic Queue
Hard 32
47.6% 69 Compare Version Numbers Two Pointers String
Medium 32
42.3% 70 Largest Rectangle in Histogram Array Stack Monotonic Stack
Hard 32
47.4% 71 Longest Palindromic Subsequence String Dynamic Programming
Medium 32
64.1% 72 Min Stack Stack Design
Medium 32
56.4% 73 Restore IP Addresses String Backtracking
Medium 32
53.2% 74 Reverse Words in a String Two Pointers String
Medium 32
51.9% 75 Pascal's Triangle Array Dynamic Programming
Easy 32
77.0% 76 Jump Game Array Dynamic Programming Greedy
Medium 32
39.5% 77 Count of Integers Math String Dynamic Programming
Hard 32
37.1% 78 Climbing Stairs Math Dynamic Programming Memoization
Easy 32
53.5% 79 Palindromic Substrings Two Pointers String Dynamic Programming
Medium 32
71.7% 80 Design Browser History Array Linked List Stack Design Doubly-Linked List Data Stream
Medium 32
77.7% 81 Maximum Product of Two Elements in an Array Array Sorting Heap (Priority Queue)
Easy 32
83.2% 82 Beautiful Arrangement Array Dynamic Programming Backtracking Bit Manipulation Bitmask
Medium 32
64.5% 83 Remove K Digits String Stack Greedy Monotonic Stack
Medium 32
34.9% 84 Product of Array Except Self Array Prefix Sum
Medium 32
67.8% 85 Number of 1 Bits Divide and Conquer Bit Manipulation
Easy 32
74.5% 86 Unique Paths II Array Dynamic Programming Matrix
Medium 32
43.2% 87 Two Sum IV - Input is a BST Hash Table Two Pointers Tree Depth-First Search Breadth-First Search Binary Search Tree Binary Tree
Easy 32
62.2%