1 Find the Smallest Divisor Given a Threshold Array Binary Search
Medium 100
0.7% 2 The kth Factor of n Math Number Theory
Medium 96
0.7% 3 Valid Triangle Number Array Two Pointers Binary Search Greedy Sorting
Medium 96
0.6% 4 The Earliest Moment When Everyone Become Friends Array Union-Find Sorting
Medium 93
0.7% 5 Minimum Swaps to Group All 1's Together Array Sliding Window
Medium 93
0.6% 6 Break a Palindrome String Greedy
Medium 93
0.5% 7 Unique Substrings With Equal Digit Frequency Hash Table String Rolling Hash Counting Hash Function
Medium 93
0.6% 8 Valid Word String
Easy 93
0.5% 9 Minimum Replacements to Sort the Array Array Math Greedy
Hard 93
0.5% 10 String Compression Two Pointers String
Medium 93
0.6% 11 Divide Players Into Teams of Equal Skill Array Hash Table Two Pointers Sorting
Medium 93
0.7% 12 Rearrange Words in a Sentence String Sorting
Medium 93
0.7% 13 Number of Good Binary Strings Dynamic Programming
Medium 93
0.5% 14 Most Visited Sector in a Circular Track Array Simulation
Easy 93
0.6% 15 Minimum One Bit Operations to Make Integers Zero Math Dynamic Programming Bit Manipulation Recursion Memoization
Hard 93
0.8% 16 Remove Duplicate Letters String Stack Greedy Monotonic Stack
Medium 84
0.5% 17 Group Anagrams Array Hash Table String Sorting
Medium 80
0.7% 18 Merge Intervals Array Sorting
Medium 80
0.5% 19 Remove Stones to Minimize the Total Array Greedy Heap (Priority Queue)
Medium 75
0.7% 20 Valid Parentheses String Stack
Easy 69
0.4% 21 Minimum Number of Chairs in a Waiting Room String Simulation
Easy 69
0.8% 22 Two Sum Array Hash Table
Easy 69
0.6% 23 Count Vowel Substrings of a String Hash Table String
Easy 69
0.7% 24 Maximum Palindromes After Operations Array Hash Table String Greedy Sorting Counting
Medium 69
0.5% 25 Find Pivot Index Array Prefix Sum
Easy 69
0.6% 26 Count and Say String
Medium 69
0.6% 27 Sliding Window Maximum Array Queue Sliding Window Heap (Priority Queue) Monotonic Queue
Hard 69
0.5% 28 Longest Substring Without Repeating Characters Hash Table String Sliding Window
Medium 62
0.4% 29 Best Time to Buy and Sell Stock Array Dynamic Programming
Easy 62
0.6% 30 House Robber Array Dynamic Programming
Medium 62
0.5% 31 Number of Islands Array Depth-First Search Breadth-First Search Union-Find Matrix
Medium 62
0.6% 32 Trapping Rain Water Array Two Pointers Dynamic Programming Stack Monotonic Stack
Hard 62
0.7% 33 Roman to Integer Hash Table Math String
Easy 62
0.7% 34 LRU Cache Hash Table Linked List Design Doubly-Linked List
Medium 62
0.5% 35 Number of Visible People in a Queue Array Stack Monotonic Stack
Hard 62
0.7% 36 Flip String to Monotone Increasing String Dynamic Programming
Medium 62
0.6% 37 Reorganize String Hash Table String Greedy Sorting Heap (Priority Queue) Counting
Medium 62
0.6% 38 Maximum Area of a Piece of Cake After Horizontal and Vertical Cuts Array Greedy Sorting
Medium 62
0.4% 39 Minimum Number of Swaps to Make the String Balanced Two Pointers String Stack Greedy
Medium 51
0.8% 40 Find the Index of the First Occurrence in a String Two Pointers String String Matching
Easy 51
0.5% 41 Degree of an Array Array Hash Table
Easy 51
0.6% 42 Rotting Oranges Array Breadth-First Search Matrix
Medium 51
0.6% 43 Container With Most Water Array Two Pointers Greedy
Medium 51
0.6% 44 Generate Parentheses String Dynamic Programming Backtracking
Medium 51
0.8% 45 Verify Preorder Sequence in Binary Search Tree Array Stack Tree Binary Search Tree Recursion Monotonic Stack Binary Tree
Medium 51
0.5% 46 Kth Smallest Element in a BST Tree Depth-First Search Binary Search Tree Binary Tree
Medium 51
0.8% 47 Word Ladder Hash Table String Breadth-First Search
Hard 51
0.5% 48 Cheapest Flights Within K Stops Dynamic Programming Depth-First Search Breadth-First Search Graph Theory Heap (Priority Queue) Shortest Path
Medium 51
0.4% 49 Minimum Value to Get Positive Step by Step Sum Array Prefix Sum
Easy 51
0.6% 50 Maximum Points You Can Obtain from Cards Array Sliding Window Prefix Sum
Medium 51
0.6% 51 Letter Combinations of a Phone Number Hash Table String Backtracking
Medium 51
0.7% 52 K-diff Pairs in an Array Array Hash Table Two Pointers Binary Search Sorting
Medium 51
0.5% 53 Reformat Date String
Easy 51
0.7% 54 Maximum Number of Events That Can Be Attended Array Greedy Sorting Heap (Priority Queue)
Medium 51
0.4% 55 Max Area of Island Array Depth-First Search Breadth-First Search Union-Find Matrix
Medium 51
0.7% 56 Basic Calculator II Math String Stack
Medium 51
0.5% 57 LFU Cache Hash Table Linked List Design Doubly-Linked List
Hard 51
0.5% 58 Validate Binary Search Tree Tree Depth-First Search Binary Search Tree Binary Tree
Medium 51
0.4% 59 Maximum Frequency Stack Hash Table Stack Design Ordered Set
Hard 51
0.7% 60 Koko Eating Bananas Array Binary Search
Medium 51
0.5% 61 Search in Rotated Sorted Array Array Binary Search
Medium 51
0.5% 62 Capacity To Ship Packages Within D Days Array Binary Search
Medium 51
0.7% 63 Palindrome Pairs Array Hash Table String Trie Hash Function
Hard 51
0.4% 64 Max Consecutive Ones III Array Binary Search Sliding Window Prefix Sum
Medium 51
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