120 | Triangle | Java | 69.0% | medium | Array, Dynamic Programming |
119 | Pascal’s Triangle II | Java | 69.2% | easy | Array, Dynamic Programming |
118 | Pascal’s Triangle | Java | 76.6% | easy | Array, Dynamic Programming |
113 | Path Sum II | Java | 63.5% | medium | Tree, Depth-First Search, Backtracking, Binary Tree |
80 | Remove Duplicates from Sorted Array II | Java | 62.3% | medium | Array, Two Pointers |
74 | Search a 2D Matrix | Java | 50.3% | medium | Array, Binary Search, Matrix |
73 | Set Matrix Zeroes | Java | 68.5% | medium | Array, Hash Table, Matrix |
71 | Simplify Path | Java | 46.1% | medium | Stack, String |
64 | Minimum Path Sum | Java | 71.1% | medium | Array, Dynamic Programming, Matrix |
29 | Divide Two Integers | Java | 22.4% | medium | Bit Manipulation, Math |
165 | Compare Version Numbers | Java | 52.9% | medium | Two Pointers, String |
474 | Ones and Zeroes | Java | 66.6% | medium | Array, String, Dynamic Programming |
518 | Coin Change II | Java | 71.2% | medium | Array, Dynamic Programming |
494 | Target Sum❤️ | Java | 48.7% | medium | Array, Dynamic Programming, Backtracking |
1049 | Last Stone Weight II | Java | 71.1% | medium | Array, Dynamic Programming |
114 | Flatten Binary Tree to Linked List | Java | 74.5% | medium | Stack, Tree, Depth-First Search, Linked List, Binary Tree |
109 | Convert Sorted List to Binary Search Tree | Java | 76.8% | medium | Tree, Binary Search Tree, Linked List, Divide and Conquer, Binary Tree |
86 | Partition List | Java | 65.2% | medium | Linked List, Two Pointers |
61 | Rotate List | Java | 41.5% | medium | Linked List, Two Pointers |
416 | Partition Equal Subset Sum | Java | 52.8% | medium | Array, Dynamic Programming |
96 | Unique Binary Search Trees | Java | 71.3% | medium | Tree, Binary Search Tree, Math, Dynamic Programming, Binary Tree |
343 | Integer Break | Java | 64.0% | medium | Math, Dynamic Programming |
63 | Unique Paths II | Java | 41.7% | medium | Array, Dynamic Programming, Matrix |
62 | Unique Paths | Java | 68.8% | medium | Math, Dynamic Programming, Combinatorics |
746 | Min Cost Climbing Stairs | Java | 67.3% | easy | Array, Dynamic Programming |
70 | Climbing Stairs | Java | 54.9% | easy | Memoization, Math, Dynamic Programming |
509 | Fibonacci Number | Java | 65.9% | easy | Recursion, Memoization, Math, Dynamic Programming |
1005 | Maximize Sum Of Array After K Negations | Java | 51.6% | easy | Greedy, Array, Sorting |
45 | Jump Game II | Java | 44.5% | medium | Greedy, Array, Dynamic Programming |
55 | Jump Game | Java | 43.5% | medium | Greedy, Array, Dynamic Programming |
121 | Best Time to Buy and Sell Stock | Java | 58.1% | easy | Array, Dynamic Programming |
122 | Best Time to Buy and Sell Stock II | Java | 74.3% | medium | Greedy, Array, Dynamic Programming |
53 | Maximum Subarray | Java | 55.7% | medium | Array, Divide and Conquer, Dynamic Programming |
376 | Wiggle Subsequence | Java | 46.3% | medium | Greedy, Array, Dynamic Programming |
455 | Assign Cookies | Java | 56.2% | easy | Greedy, Array, Two Pointers, Sorting |
90 | Subsets II | Java | 63.5% | medium | Bit Manipulation, Array, Backtracking |
47 | Permutations II | Java | 66.0% | medium | Array, Backtracking |
89 | Gray Code | Java | 75.4% | medium | Bit Manipulation, Math, Backtracking |
79 | Word Search | Java | 47.7% | medium | Array, String, Backtracking, Matrix |
37 | Sudoku Solver | Java | 68.1% | hard | Array, Hash Table, Backtracking, Matrix |
52 | N-Queens II | Java | 82.4% | hard | Backtracking |
51 | N-Queens❤️ | Java | 74.5% | hard | Array, Backtracking |
332 | Reconstruct Itinerary❤️ | Java | 44.6% | hard | Depth-First Search, Graph, Eulerian Circuit |
93 | Restore IP Addresses | Java | 60.3% | medium | String, Backtracking |
491 | Non-decreasing Subsequences | Java | 52.1% | medium | Bit Manipulation, Array, Hash Table, Backtracking |
90 | Subsets II | Java | 63.5% | medium | Bit Manipulation, Array, Backtracking |
78 | Subsets | Java | 81.7% | medium | Bit Manipulation, Array, Backtracking |
47 | Permutations II | Java | 66.0% | medium | Array, Backtracking |
46 | Permutations | Java | 79.8% | medium | Array, Backtracking |
131 | Palindrome Partitioning | Java | 74.1% | medium | String, Dynamic Programming, Backtracking |
40 | Combination Sum II | Java | 59.6% | medium | Array, Backtracking |
39 | Combination Sum | Java | 73.2% | medium | Array, Backtracking |
17 | Letter Combinations of a Phone Number | Java | 60.7% | medium | Hash Table, String, Backtracking |
216 | Combination Sum III | Java | 71.4% | medium | Array, Backtracking |
77 | Combinations | Java | 77.4% | medium | Backtracking |
99 | Recover Binary Search Tree | Java | 60.9% | medium | Tree, Depth-First Search, Binary Search Tree, Binary Tree |
95 | Unique Binary Search Trees II | Java | 74.2% | medium | Tree, Binary Search Tree, Dynamic Programming, Backtracking, Binary Tree |
1038 | Binary Search Tree to Greater Sum Tree | Java | 83.7% | medium | Tree, Depth-First Search, Binary Search Tree, Binary Tree |
538 | Convert BST to Greater Tree | Java | 77.9% | medium | Tree, Depth-First Search, Binary Search Tree, Binary Tree |
108 | Convert Sorted Array to Binary Search Tree | Java | 79.3% | easy | Tree, Binary Search Tree, Array, Divide and Conquer, Binary Tree |
669 | Trim a Binary Search Tree | Java | 67.1% | medium | Tree, Depth-First Search, Binary Search Tree, Binary Tree |
450 | Delete Node in a BST | Java | 52.5% | medium | Tree, Binary Search Tree, Binary Tree |
235 | Lowest Common Ancestor of a Binary Search Tree | Java | 70.9% | medium | Tree, Depth-First Search, Binary Search Tree, Binary Tree |
236 | Lowest Common Ancestor of a Binary Tree | Java | 72.2% | medium | Tree, Depth-First Search, Binary Tree |
701 | Insert into a Binary Search Tree | Java | 70.0% | medium | Tree, Binary Search Tree, Binary Tree |
501 | Find Mode in Binary Search Tree | Java | 55.7% | easy | Tree, Depth-First Search, Binary Search Tree, Binary Tree |
783 | Minimum Distance Between BST Nodes | Java | 60.5% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Search Tree, Binary Tree |
530 | Minimum Absolute Difference in BST | Java | 62.9% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Search Tree, Binary Tree |
98 | Validate Binary Search Tree | Java | 38.5% | medium | Tree, Depth-First Search, Binary Search Tree, Binary Tree |
700 | Search in a Binary Search Tree | Java | 78.6% | easy | Tree, Binary Search Tree, Binary Tree |
617 | Merge Two Binary Trees | Java | 79.5% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
654 | Maximum Binary Tree | Java | 82.2% | medium | Stack, Tree, Array, Divide and Conquer, Binary Tree, Monotonic Stack |
110 | Balanced Binary Tree | Java | 58.8% | easy | Tree, Depth-First Search, Binary Tree |
106 | Construct Binary Tree from Inorder and Postorder Traversal | Java | 72.5% | medium | Tree, Array, Hash Table, Divide and Conquer, Binary Tree |
105 | Construct Binary Tree from Preorder and Inorder Traversal | Java | 72.1% | medium | Tree, Array, Hash Table, Divide and Conquer, Binary Tree |
112 | Path Sum | Java | 54.7% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
513 | Find Bottom Left Tree Value | Java | 73.4% | medium | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
404 | Sum of Left Leaves | Java | 63.3% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
257 | Binary Tree Paths | Java | 71.1% | easy | Tree, Depth-First Search, String, Backtracking, Binary Tree |
222 | Count Complete Tree Nodes | Java | 82.1% | easy | Bit Manipulation, Tree, Binary Search, Binary Tree |
101 | Symmetric Tree | Java | 61.2% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
226 | Invert Binary Tree | Java | 81.1% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
117 | Populating Next Right Pointers in Each Node II | Java | 70.4% | medium | Tree, Depth-First Search, Breadth-First Search, Linked List, Binary Tree |
116 | Populating Next Right Pointers in Each Node | Java | 73.9% | medium | Tree, Depth-First Search, Breadth-First Search, Linked List, Binary Tree |
111 | Minimum Depth of Binary Tree | Java | 54.9% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
104 | Maximum Depth of Binary Tree | Java | 78.0% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
515 | Find Largest Value in Each Tree Row | Java | 66.5% | medium | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
429 | N-ary Tree Level Order Traversal | Java | 74.0% | medium | Tree, Breadth-First Search |
637 | Average of Levels in Binary Tree | Java | 71.2% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
199 | Binary Tree Right Side View | Java | 68.1% | medium | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
107 | Binary Tree Level Order Traversal II | Java | 74.6% | medium | Tree, Breadth-First Search, Binary Tree |
102 | Binary Tree Level Order Traversal | Java | 68.3% | medium | Tree, Breadth-First Search, Binary Tree |
347 | Top K Frequent Elements | Java | 64.1% | medium | Array, Hash Table, Divide and Conquer, Bucket Sort, Counting, Quickselect, Sorting, Heap (Priority Queue) |
145 | Binary Tree Postorder Traversal | Java | 77.0% | easy | Stack, Tree, Depth-First Search, Binary Tree |
144 | Binary Tree Preorder Traversal | Java | 72.3% | easy | Stack, Tree, Depth-First Search, Binary Tree |
94 | Binary Tree Inorder Traversal | Java | 77.4% | easy | Stack, Tree, Depth-First Search, Binary Tree |
145 | Binary Tree Postorder Traversal | Java | 77.0% | easy | Stack, Tree, Depth-First Search, Binary Tree |
144 | Binary Tree Preorder Traversal | Java | 72.3% | easy | Stack, Tree, Depth-First Search, Binary Tree |
239 | Sliding Window Maximum | Java | 49.1% | hard | Queue, Array, Sliding Window, Monotonic Queue, Heap (Priority Queue) |
150 | Evaluate Reverse Polish Notation | Java | 55.4% | medium | Stack, Array, Math |
1047 | Remove All Adjacent Duplicates In String | Java | 72.9% | easy | Stack, String |
20 | Valid Parentheses | Java | 44.3% | easy | Stack, String |
225 | Implement Stack using Queues | Java | 65.7% | easy | Stack, Design, Queue |
232 | Implement Queue using Stacks | Java | 68.2% | easy | Stack, Design, Queue |
459 | Repeated Substring Pattern | Java | 51.9% | easy | String, String Matching |
28 | Find the Index of the First Occurrence in a String | Java | 44.2% | easy | Two Pointers, String, String Matching |
796 | Rotate String | Java | 63.9% | easy | String, String Matching |
151 | Reverse Words in a String | Java | 56.9% | medium | Two Pointers, String |
541 | Reverse String II | Java | 57.6% | easy | Two Pointers, String |
202 | Happy Number | Java | 65.1% | easy | Hash Table, Math, Two Pointers |
349 | Intersection of Two Arrays | Java | 75.0% | easy | Array, Hash Table, Two Pointers, Binary Search, Sorting |
707 | Design Linked List | Java | 34.6% | medium | Design, Linked List |
344 | Reverse String | Java | 80.5% | easy | Two Pointers, String |
383 | Ransom Note | Java | 65.6% | easy | Hash Table, String, Counting |
202 | Happy Number | Java | 65.1% | easy | Hash Table, Math, Two Pointers |
242 | Valid Anagram | Java | 67.0% | easy | Hash Table, String, Sorting |
19 | Remove Nth Node From End of List | Java | 49.5% | medium | Linked List, Two Pointers |
24 | Swap Nodes in Pairs | Java | 73.1% | medium | Recursion, Linked List |
203 | Remove Linked List Elements | Java | 57.7% | easy | Recursion, Linked List |
59 | Spiral Matrix II | Java | 70.7% | medium | Array, Matrix, Simulation |
2401 | Longest Nice Subarray | Java | 54.1% | medium | Bit Manipulation, Array, Sliding Window |
76 | Minimum Window Substring | Java | 46.4% | hard | Hash Table, String, Sliding Window |
904 | Fruit Into Baskets | Java | 45.4% | medium | Array, Hash Table, Sliding Window |
209 | Minimum Size Subarray Sum | Java | 46.8% | medium | Array, Binary Search, Prefix Sum, Sliding Window |
88 | Merge Sorted Array | Java | 54.2% | easy | Array, Two Pointers, Sorting |
977 | Squares of a Sorted Array | Java | 68.7% | easy | Array, Two Pointers, Sorting |
844 | Backspace String Compare | Java | 47.9% | easy | Stack, Two Pointers, String, Simulation |
283 | Move Zeroes | Java | 63.8% | easy | Array, Two Pointers |
27 | Remove Element | Java | 60.0% | easy | Array, Two Pointers |
367 | Valid Perfect Square | Java | 45.1% | easy | Math, Binary Search |
69 | Sqrt(x) | Java | 38.6% | easy | Math, Binary Search |
35 | Search Insert Position | Java | 47.1% | easy | Array, Binary Search |
2 | Add Two Numbers | Java | 44.5% | medium | Recursion, Linked List, Math |
142 | Linked List Cycle II | Java | 59.9% | medium | Hash Table, Linked List, Two Pointers |
141 | Linked List Cycle | Java | 52.9% | easy | Hash Table, Linked List, Two Pointers |
225 | Implement Stack using Queues | Java | 65.7% | easy | Stack, Design, Queue |
232 | Implement Queue using Stacks | Java | 68.2% | easy | Stack, Design, Queue |
503 | Next Greater Element II | Java | 68.2% | medium | Stack, Array, Monotonic Stack |
496 | Next Greater Element I | Java | 72.2% | easy | Stack, Array, Hash Table, Monotonic Stack |
503 | Next Greater Element II | Java | 68.2% | medium | Stack, Array, Monotonic Stack |
36 | Valid Sudoku | Java | 63.8% | medium | Array, Hash Table, Matrix |
38 | Count and Say | Java | 61.1% | medium | String |
100 | Same Tree | Java | 62.3% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
148 | Sort List | Java | 66.2% | medium | Linked List, Two Pointers, Divide and Conquer, Sorting, Merge Sort |
69 | Sqrt(x) | Java | 38.6% | easy | Math, Binary Search |
1103 | Distribute Candies to People | Java | 67.8% | easy | Math, Simulation |
61 | Rotate List | Java | 41.5% | medium | Linked List, Two Pointers |
57 | Insert Interval | Java | 42.7% | medium | Array |
58 | Length of Last Word | Java | 46.7% | easy | String |
57 | Insert Interval | Java | 42.7% | medium | Array |
56 | Merge Intervals | Java | 50.6% | medium | Array, Sorting |
59 | Spiral Matrix II | Java | 70.7% | medium | Array, Matrix, Simulation |
54 | Spiral Matrix | Java | 52.0% | medium | Array, Matrix, Simulation |
1221 | Split a String in Balanced Strings | Java | 85.4% | easy | Greedy, String, Counting |
50 | Pow(x, n) | Java | 38.6% | medium | Recursion, Math |
49 | Group Anagrams | Java | 68.9% | medium | Array, Hash Table, String, Sorting |
48 | Rotate Image | Java | 77.2% | medium | Array, Math, Matrix |
47 | Permutations II | Java | 66.0% | medium | Array, Backtracking |
46 | Permutations | Java | 79.8% | medium | Array, Backtracking |
45 | Jump Game II | Java | 44.5% | medium | Greedy, Array, Dynamic Programming |
55 | Jump Game | Java | 43.5% | medium | Greedy, Array, Dynamic Programming |
43 | Multiply Strings | Java | 44.5% | medium | Math, String, Simulation |
415 | Add Strings | Java | 54.6% | easy | Math, String, Simulation |
41 | First Missing Positive | Java | 45.7% | hard | Array, Hash Table |
42 | Trapping Rain Water | Java | 64.3% | hard | Stack, Array, Two Pointers, Dynamic Programming, Monotonic Stack |
40 | Combination Sum II | Java | 59.6% | medium | Array, Backtracking |
39 | Combination Sum | Java | 73.2% | medium | Array, Backtracking |
35 | Search Insert Position | Java | 47.1% | easy | Array, Binary Search |
34 | Find First and Last Position of Element in Sorted Array | Java | 44.2% | medium | Array, Binary Search |
33 | Search in Rotated Sorted Array | Java | 44.6% | medium | Array, Binary Search |
31 | Next Permutation | Java | 40.0% | medium | Array, Two Pointers |
28 | Find the Index of the First Occurrence in a String | Java | 44.2% | easy | Two Pointers, String, String Matching |
25 | Reverse Nodes in k-Group | Java | 68.6% | hard | Recursion, Linked List |
92 | Reverse Linked List II | Java | 56.8% | medium | Linked List |
206 | Reverse Linked List | Java | 75.1% | easy | Recursion, Linked List |
24 | Swap Nodes in Pairs | Java | 73.1% | medium | Recursion, Linked List |
26 | Remove Duplicates from Sorted Array | Java | 57.2% | easy | Array, Two Pointers |
27 | Remove Element | Java | 60.0% | easy | Array, Two Pointers |
23 | Merge k Sorted Lists | Java | 60.6% | hard | Linked List, Divide and Conquer, Heap (Priority Queue), Merge Sort |
17 | Letter Combinations of a Phone Number | Java | 60.7% | medium | Hash Table, String, Backtracking |
22 | Generate Parentheses | Java | 78.2% | medium | String, Dynamic Programming, Backtracking |
21 | Merge Two Sorted Lists | Java | 67.1% | easy | Recursion, Linked List |
20 | Valid Parentheses | Java | 44.3% | easy | Stack, String |
19 | Remove Nth Node From End of List | Java | 49.5% | medium | Linked List, Two Pointers |
18 | 4Sum | Java | 36.6% | medium | Array, Two Pointers, Sorting |
16 | 3Sum Closest | Java | 44.8% | medium | Array, Two Pointers, Sorting |
17 | Letter Combinations of a Phone Number | Java | 60.7% | medium | Hash Table, String, Backtracking |
15 | 3Sum | Java | 38.5% | medium | Array, Two Pointers, Sorting |
14 | Longest Common Prefix | Java | 44.4% | easy | Trie, String |
13 | Roman to Integer | Java | 63.5% | easy | Hash Table, Math, String |
12 | Integer to Roman | Java | 67.9% | medium | Hash Table, Math, String |
11 | Container With Most Water | Java | 60.7% | medium | Greedy, Array, Two Pointers |
8 | String to Integer (atoi) | Java | 21.4% | medium | String |
7 | Reverse Integer | Java | 35.6% | medium | Math |
6 | Zigzag Conversion | Java | 53.3% | medium | String |
5 | Longest Palindromic Substring❤️ | Java | 38.8% | medium | Two Pointers, String, Dynamic Programming |
3 | Longest Substring Without Repeating Characters❤️ | Java | 40.3% | medium | Hash Table, String, Sliding Window |
2 | Add Two Numbers | Java | 44.5% | medium | Recursion, Linked List, Math |
1 | Two Sum | Java | 54.3% | easy | Array, Hash Table |
2129 | Capitalize the Title | Java | 70.8% | easy | String |
2171 | Removing Minimum Number of Magic Beans | Java | 48.3% | medium | Greedy, Array, Enumeration, Prefix Sum, Sorting |
2719 | Count of Integers | Java | 55.1% | hard | Math, String, Dynamic Programming |
2744 | Find Maximum Number of String Pairs | Java | 86.2% | easy | Array, Hash Table, String, Simulation |
82 | Remove Duplicates from Sorted List II | Java | 54.7% | medium | Linked List, Two Pointers |
200 | Number of Islands | Java | 61.5% | medium | Depth-First Search, Breadth-First Search, Union Find, Array, Matrix |
695 | Max Area of Island | Java | 68.3% | medium | Depth-First Search, Breadth-First Search, Union Find, Array, Matrix |
107 | Binary Tree Level Order Traversal II | Java | 74.6% | medium | Tree, Breadth-First Search, Binary Tree |
111 | Minimum Depth of Binary Tree | Java | 54.9% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
103 | Binary Tree Zigzag Level Order Traversal | Java | 59.5% | medium | Tree, Breadth-First Search, Binary Tree |
102 | Binary Tree Level Order Traversal | Java | 68.3% | medium | Tree, Breadth-First Search, Binary Tree |
101 | Symmetric Tree | Java | 61.2% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
100 | Same Tree | Java | 62.3% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
82 | Remove Duplicates from Sorted List II | Java | 54.7% | medium | Linked List, Two Pointers |
83 | Remove Duplicates from Sorted List | Java | 54.2% | easy | Linked List |
141 | Linked List Cycle | Java | 52.9% | easy | Hash Table, Linked List, Two Pointers |
7 | Reverse Integer | Java | 35.6% | medium | Math |
232 | Implement Queue using Stacks | Java | 68.2% | easy | Stack, Design, Queue |
225 | Implement Stack using Queues | Java | 65.7% | easy | Stack, Design, Queue |
67 | Add Binary | Java | 53.5% | easy | Bit Manipulation, Math, String, Simulation |
146 | LRU Cache | Java | 54.0% | medium | Design, Hash Table, Linked List, Doubly-Linked List |
704 | Binary Search | Java | 55.9% | easy | Array, Binary Search |
912 | Sort an Array | Java | 48.6% | medium | Array, Divide and Conquer, Bucket Sort, Counting Sort, Radix Sort, Sorting, Heap (Priority Queue), Merge Sort |
590 | N-ary Tree Postorder Traversal | Java | 79.7% | easy | Stack, Tree, Depth-First Search |
190 | Reverse Bits | Java | 73.2% | easy | Bit Manipulation, Divide and Conquer |
136 | Single Number | Java | 74.4% | easy | Bit Manipulation, Array |
21 | Merge Two Sorted Lists | Java | 67.1% | easy | Recursion, Linked List |
206 | Reverse Linked List | Java | 75.1% | easy | Recursion, Linked List |
231 | Power of Two | Java | 49.8% | easy | Bit Manipulation, Recursion, Math |
191 | Number of 1 Bits | Java | 78.1% | easy | Bit Manipulation, Divide and Conquer |
3 | Longest Substring Without Repeating Characters❤️ | Java | 40.3% | medium | Hash Table, String, Sliding Window |
19 | Remove Nth Node From End of List | Java | 49.5% | medium | Linked List, Two Pointers |
876 | Middle of the Linked List | Java | 71.5% | easy | Linked List, Two Pointers |
557 | Reverse Words in a String III | Java | 73.7% | easy | Two Pointers, String |
344 | Reverse String | Java | 80.5% | easy | Two Pointers, String |
167 | Two Sum II - Input Array Is Sorted | Java | 60.4% | medium | Array, Two Pointers, Binary Search |
189 | Rotate Array | Java | 45.8% | medium | Array, Math, Two Pointers |
977 | Squares of a Sorted Array | Java | 68.7% | easy | Array, Two Pointers, Sorting |
70 | Climbing Stairs | Java | 54.9% | easy | Memoization, Math, Dynamic Programming |
589 | N-ary Tree Preorder Traversal | Java | 76.0% | easy | Stack, Tree, Depth-First Search |
2055 | Plates Between Candles | Java | 44.0% | medium | Array, String, Binary Search, Prefix Sum |
2100 | Find Good Days to Rob the Bank | Java | 48.7% | medium | Array, Dynamic Programming, Prefix Sum |
11 | Container With Most Water | Java | 60.7% | medium | Greedy, Array, Two Pointers |
504 | Base 7 | Java | 51.9% | easy | Math |
LCR 076 | 数组中的第 K 个最大元素 | Java | 65.1% | medium | Array, Divide and Conquer, Quickselect, Sorting, Heap (Priority Queue) |
239 | Sliding Window Maximum | Java | 49.1% | hard | Queue, Array, Sliding Window, Monotonic Queue, Heap (Priority Queue) |
LCR 183 | 望远镜中最高的海拔 | Java | 44.6% | hard | Queue, Array, Sliding Window, Monotonic Queue, Heap (Priority Queue) |
15 | 3Sum | Java | 38.5% | medium | Array, Two Pointers, Sorting |
258 | Add Digits | Java | 70.4% | easy | Math, Number Theory, Simulation |
102 | Binary Tree Level Order Traversal | Java | 68.3% | medium | Tree, Breadth-First Search, Binary Tree |
101 | Symmetric Tree | Java | 61.2% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
9 | Palindrome Number | Java | 56.2% | easy | Math |
LCR 172 | 统计目标成绩的出现次数 | Java | 52.7% | easy | Array, Binary Search |
LCR 173 | 点名 | Java | 44.8% | easy | Bit Manipulation, Array, Hash Table, Math, Binary Search |
LCR 174 | 寻找二叉搜索树中的目标节点 | Java | 76.4% | easy | Tree, Depth-First Search, Binary Search Tree, Binary Tree |
94 | Binary Tree Inorder Traversal | Java | 77.4% | easy | Stack, Tree, Depth-First Search, Binary Tree |
LCR 175 | 计算二叉树的深度 | Java | 79.3% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
LCR 176 | 判断是否为平衡二叉树 | Java | 59.5% | easy | Tree, Depth-First Search, Binary Tree |
110 | Balanced Binary Tree | Java | 58.8% | easy | Tree, Depth-First Search, Binary Tree |
6 | Zigzag Conversion | Java | 53.3% | medium | String |
217 | Contains Duplicate | Java | 55.4% | easy | Array, Hash Table, Sorting |
344 | Reverse String | Java | 80.5% | easy | Two Pointers, String |
283 | Move Zeroes | Java | 63.8% | easy | Array, Two Pointers |
237 | Delete Node in a Linked List | Java | 86.5% | medium | Linked List |
104 | Maximum Depth of Binary Tree | Java | 78.0% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
225 | Implement Stack using Queues | Java | 65.7% | easy | Stack, Design, Queue |
232 | Implement Queue using Stacks | Java | 68.2% | easy | Stack, Design, Queue |
977 | Squares of a Sorted Array | Java | 68.7% | easy | Array, Two Pointers, Sorting |
553 | Optimal Division | Java | 64.8% | medium | Array, Math, Dynamic Programming |
122 | Best Time to Buy and Sell Stock II | Java | 74.3% | medium | Greedy, Array, Dynamic Programming |
26 | Remove Duplicates from Sorted Array | Java | 57.2% | easy | Array, Two Pointers |
35 | Search Insert Position | Java | 47.1% | easy | Array, Binary Search |
278 | First Bad Version | Java | 45.7% | easy | Binary Search, Interactive |
704 | Binary Search | Java | 55.9% | easy | Array, Binary Search |
LCR 188 | 买卖芯片的最佳时机 | Java | 62.6% | medium | Array, Dynamic Programming |
2016 | Maximum Difference Between Increasing Elements | Java | 60.0% | easy | Array |
LCR 159 | 库存管理 III | Java | 57.8% | easy | Array, Divide and Conquer, Quickselect, Sorting, Heap (Priority Queue) |
146 | LRU Cache | Java | 54.0% | medium | Design, Hash Table, Linked List, Doubly-Linked List |
LCR 158 | 库存管理 II | Java | 69.8% | easy | Array, Hash Table, Divide and Conquer, Counting, Sorting |
LCR 153 | 二叉树中和为目标值的路径 | Java | 59.2% | medium | Tree, Depth-First Search, Backtracking, Binary Tree |
LCR 152 | 验证二叉搜索树的后序遍历序列 | Java | 57.0% | medium | Stack, Tree, Binary Search Tree, Recursion, Array, Binary Tree, Monotonic Stack |
LCR 151 | 彩灯装饰记录 III | Java | 58.2% | medium | Tree, Breadth-First Search, Binary Tree |
LCR 149 | 彩灯装饰记录 I | Java | 63.0% | medium | Tree, Breadth-First Search, Binary Tree |
LCR 150 | 彩灯装饰记录 II | Java | 68.7% | easy | Tree, Breadth-First Search, Binary Tree |
LCR 148 | 验证图书取出顺序 | Java | 61.1% | medium | Stack, Array, Simulation |
LCR 147 | 最小栈 | Java | 55.3% | easy | Stack, Design |
LCR 146 | 螺旋遍历二维数组 | Java | 42.1% | easy | Array, Matrix, Simulation |
LCR 145 | 判断对称二叉树 | Java | 57.7% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
LCR 144 | 翻转二叉树 | Java | 79.5% | easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
LCR 142 | 训练计划 IV | Java | 71.8% | easy | Recursion, Linked List |
LCR 022 | 环形链表 II | Java | 55.7% | medium | Hash Table, Linked List, Two Pointers |
141 | Linked List Cycle | Java | 52.9% | easy | Hash Table, Linked List, Two Pointers |
LCR 141 | 训练计划 III | Java | 74.1% | easy | Recursion, Linked List |
141 | Linked List Cycle | Java | 52.9% | easy | Hash Table, Linked List, Two Pointers |
LCR 140 | 训练计划 II | Java | 79.5% | easy | Linked List, Two Pointers |
LCR 139 | 训练计划 I | Java | 65.0% | easy | Array, Two Pointers, Sorting |
LCR 136 | 删除链表的节点 | Java | 59.2% | easy | Linked List |
LCR 135 | 报数 | Java | 77.6% | easy | Array, Math |
LCR 134 | Pow(x, n) | Java | 35.2% | medium | Recursion, Math |
LCR 133 | 位 1 的个数 | Java | 76.1% | easy | Bit Manipulation |
LCR 131 | 砍竹子 I | Java | 57.4% | medium | Math, Dynamic Programming |
LCR 128 | 库存管理 I | Java | 49.6% | easy | Array, Binary Search |
153 | Find Minimum in Rotated Sorted Array | Java | 58.0% | medium | Array, Binary Search |
704 | Binary Search | Java | 55.9% | easy | Array, Binary Search |
912 | Sort an Array | Java | 48.6% | medium | Array, Divide and Conquer, Bucket Sort, Counting Sort, Radix Sort, Sorting, Heap (Priority Queue), Merge Sort |
LCR 128 | 库存管理 I | Java | 49.6% | easy | Array, Binary Search |
LCR 125 | 图书整理 II | Java | 70.4% | easy | Stack, Design, Queue |
LCR 127 | 跳跃训练 | Java | 45.3% | easy | Memoization, Math, Dynamic Programming |
LCR 126 | 斐波那契数 | Java | 35.7% | easy | Memoization, Math, Dynamic Programming |
LCR 124 | 推理二叉树 | Java | 70.1% | medium | Tree, Array, Hash Table, Divide and Conquer, Binary Tree |
LCR 123 | 图书整理 I | Java | 73.9% | easy | Stack, Recursion, Linked List, Two Pointers |
LCR 122 | 路径加密 | Java | 74.9% | easy | String |
LCR 121 | 寻找目标值 - 二维数组 | Java | 39.5% | medium | Array, Binary Search, Divide and Conquer, Matrix |
LCR 120 | 寻找文件副本 | Java | 66.9% | easy | Array, Hash Table, Sorting |
LCR 122 | 路径加密 | Java | 74.9% | easy | String |
240 | Search a 2D Matrix II | Java | 54.5% | medium | Array, Binary Search, Divide and Conquer, Matrix |
LCR 121 | 寻找目标值 - 二维数组 | Java | 39.5% | medium | Array, Binary Search, Divide and Conquer, Matrix |
LCR 120 | 寻找文件副本 | Java | 66.9% | easy | Array, Hash Table, Sorting |
6 | Zigzag Conversion | Java | 53.3% | medium | String |
5 | Longest Palindromic Substring❤️ | Java | 38.8% | medium | Two Pointers, String, Dynamic Programming |
4 | Median of Two Sorted Arrays | Java | 42.7% | hard | Array, Binary Search, Divide and Conquer |
1 | Two Sum | Java | 54.3% | easy | Array, Hash Table |
4 | Median of Two Sorted Arrays | Java | 42.7% | hard | Array, Binary Search, Divide and Conquer |
319 | Bulb Switcher | Java | 57.8% | medium | Brainteaser, Math |
66 | Plus One | Java | 46.2% | easy | Array, Math |
350 | Intersection of Two Arrays II | Java | 57.9% | easy | Array, Hash Table, Two Pointers, Binary Search, Sorting |
349 | Intersection of Two Arrays | Java | 75.0% | easy | Array, Hash Table, Two Pointers, Binary Search, Sorting |
189 | Rotate Array | Java | 45.8% | medium | Array, Math, Two Pointers |
217 | Contains Duplicate | Java | 55.4% | easy | Array, Hash Table, Sorting |
136 | Single Number | Java | 74.4% | easy | Bit Manipulation, Array |
189 | Rotate Array | Java | 45.8% | medium | Array, Math, Two Pointers |
26 | Remove Duplicates from Sorted Array | Java | 57.2% | easy | Array, Two Pointers |
136 | Single Number | Java | 74.4% | easy | Bit Manipulation, Array |
26 | Remove Duplicates from Sorted Array | Java | 57.2% | easy | Array, Two Pointers |
3 | Longest Substring Without Repeating Characters❤️ | Java | 40.3% | medium | Hash Table, String, Sliding Window |
2 | Add Two Numbers | Java | 44.5% | medium | Recursion, Linked List, Math |
1 | Two Sum | Java | 54.3% | easy | Array, Hash Table |
75 | Sort Colors | Java | 61.8% | medium | Array, Two Pointers, Sorting |
83 | Remove Duplicates from Sorted List | Java | 54.2% | easy | Linked List |
92 | Reverse Linked List II | Java | 56.8% | medium | Linked List |
206 | Reverse Linked List | Java | 75.1% | easy | Recursion, Linked List |
70 | Climbing Stairs | Java | 54.9% | easy | Memoization, Math, Dynamic Programming |
189 | Rotate Array | Java | 45.8% | medium | Array, Math, Two Pointers |