| 1 |
Two Sum |
Solution |
O(n) |
O(n) |
|
Easy |
HashMap |
| 2 |
Add Two Numbers |
Solution |
O(max(m,n)) |
O(1) |
|
Medium |
LinkedList |
| 3 |
Longest Substring Without Repeating Characters |
Solution |
O(n) |
O(k) |
|
Medium |
HashMap, Sliding Window |
| 4 |
Median of Two Sorted Arrays |
Solution |
? |
? |
|
Hard |
Divide and Conquer |
| 5 |
Longest Palindromic Substring |
Solution |
O(n^2) |
O(1) |
|
Medium |
|
| 6 |
ZigZag Conversion |
Solution |
O(n) |
O(n) |
|
Easy |
|
| 7 |
Reverse Integer |
Solution |
O(1) |
O(1) |
|
Easy |
|
| 8 |
String to Integer (atoi) |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 9 |
Palindrome Number |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 10 |
Regular Expression Matching |
Solution |
O(m*n) |
O(m*n) |
|
Hard |
DP |
| 11 |
Container With Most Water |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 12 |
Integer to Roman |
Solution |
O(1) |
O(1) |
|
Medium |
Math, String |
| 13 |
Roman to Integer |
Solution |
O(1) |
O(1) |
|
Easy |
Math, String |
| 14 |
Longest Common Prefix |
Solution |
O(S) (S is the sum of all characters in all strings) |
O(1) |
|
Easy |
|
| 15 |
3Sum |
Solution |
O(n^2) |
O(1) |
|
Medium |
Two Pointers, Binary Search |
| 16 |
3Sum Closest |
Solution |
O(nlogn) |
O(1) |
|
Medium |
Two Pointers |
| 17 |
Letter Combinations of a Phone Number |
Solution |
O(n*4^n) |
O(n) |
|
Medium |
Backtracking |
| 18 |
4 Sum |
Solution |
O(n^2) |
O(1) |
|
Medium |
Two Pointers |
| 19 |
Remove Nth Node From End of List |
Solution |
O(n) |
O(1) |
|
Medium |
Linked List |
| 20 |
Valid Parentheses |
Solution |
O(n) |
O(n) |
|
Easy |
Stack |
| 21 |
Merge Two Sorted Lists |
Solution |
O(n) |
O(h) |
|
Easy |
Recursion |
| 22 |
Generate Parentheses |
Solution |
TBD |
O(n) |
|
Medium |
Backtracking |
| 23 |
Merge k Sorted Lists |
Solution |
O(n*logk) |
O(k) |
|
Hard |
Heap |
| 24 |
Swap Nodes in Pairs |
Solution |
O(n) |
O(h) |
|
Medium |
Recursion, LinkedList |
| 25 |
Reverse Nodes in k-Group |
Solution |
O(n) |
O(1) |
|
Hard |
Recursion, LinkedList |
| 26 |
Remove Duplicates from Sorted Array |
Solution |
O(n) |
O(1) |
|
Easy |
Array |
| 27 |
Remove Element |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 28 |
Implement strStr() |
Solution |
O(n) |
O(1) |
|
Easy |
String |
| 29 |
Divide Two Integers |
Solution |
O(?) |
O(?) |
|
Medium |
|
| 30 |
Substring with Concatenation of All Words |
Solution |
O(n^2) |
O(n) |
|
Hard |
HashMap |
| 31 |
Next Permutation |
Solution |
O(n) |
O(1) |
|
Medium |
Array |
| 32 |
Longest Valid Parentheses |
Solution |
O(n) |
O(n) |
|
Hard |
Stack, DP |
| 33 |
Search in Rotated Sorted Array |
Solution |
O(logn) |
O(1) |
|
Medium |
Binary Search |
| 34 |
Search for a Range |
Solution |
O(logn) |
O(1) |
|
Medium |
Array, Binary Search |
| 35 |
Search Insert Position |
Solution |
O(n) |
O(1) |
|
Easy |
Array |
| 36 |
Valid Sudoku |
Solution |
O(1) |
O(1) |
|
Medium |
|
| 37 |
Sudoku Solver |
Solution |
O((9!)^9) |
O(1) |
|
Hard |
|
| 38 |
Count and Say |
Solution |
O(n*2^n) |
O(2^n) |
|
Easy |
Recursion, LinkedList |
| 39 |
Combination Sum |
Solution |
O(k*n^k) |
O(k) |
|
Medium |
Backtracking |
| 40 |
Combination Sum II |
Solution |
O(k*n^k) |
O(k) |
|
Medium |
Backtracking |
| 41 |
First Missing Positive |
Solution |
O(n) |
O(1) |
|
Hard |
Array |
| 42 |
Trapping Rain Water |
Solution |
O(n) |
O(1) |
|
Hard |
|
| 43 |
Multiply Strings |
Solution |
O(n) |
O(1) |
|
Medium |
Array, String |
| 44 |
Wildcard Matching |
Solution |
O(m*n) |
O(m*n) |
|
Hard |
Backtracking, DP, Greedy, String |
| 45 |
Jump Game II |
Solution |
O(n) |
O(1) |
|
Hard |
Array, Greedy |
| 46 |
Permutations |
Solution |
O(n*n!) |
O(n) |
|
Medium |
Backtracking |
| 47 |
Permutations II |
Solution |
O(n*n!) |
O(n) |
|
Medium |
Backtracking |
| 48 |
Rotate Image |
Solution |
O(n^2) |
O(1) |
|
Medium |
Array |
| 49 |
Group Anagrams |
Solution |
O(m*klogk) |
O(m*k) |
|
Medium |
HashMap |
| 50 |
Pow(x, n) |
Solution |
O(logn) |
O(logn) |
|
Medium |
|
| 51 |
N-Queens |
Solution |
O(n!) |
O(n) |
|
Hard |
|
| 52 |
N-Queens II |
Solution |
O(n!) |
O(n) |
|
Hard |
Backtracking |
| 53 |
Maximum Subarray |
Solution |
O(n) |
O(1) |
|
Easy |
Array |
| 54 |
Spiral Matrix |
Solution |
O(m*n) |
O(m*n) |
|
Medium |
Array |
| 55 |
Jump Game |
Solution |
O(n) |
O(1) |
|
Medium |
Greedy |
| 56 |
Merge Intervals |
Solution |
O(n*logn) |
O(1) |
|
Medium |
Array, Sort |
| 57 |
Insert Intervals |
Solution |
O(n) |
O(1) |
|
Hard |
Array, Sort |
| 58 |
Length of Last Word |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 59 |
Spiral Matrix II |
Solution |
O(n) |
O(n) |
|
Medium |
|
| 60 |
Permutation Sequence |
Solution |
O(n^2) |
O(n) |
|
Medium |
Math, Backtracking |
| 61 |
Rotate List |
Solution |
O(n) |
O(1) |
|
Medium |
Linked List |
| 62 |
Unique Paths |
Solution |
O(m*n) |
O(m*n) |
|
Medium |
DP |
| 63 |
Unique Paths II |
Solution |
O(m*n) |
O(m*n) |
|
Medium |
DP |
| 64 |
Minimum Path Sum |
Solution |
O(m*n) |
O(m*n) |
|
Medium |
DP |
| 65 |
Valid Number |
Solution |
O(n) |
O(1) |
|
Hard |
|
| 66 |
Plus One |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 67 |
Add Binary |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 68 |
Text Justification |
Solution |
O(n) |
O(1) |
|
Hard |
|
| 69 |
Sqrt(x) |
Solution |
O(logn) |
O(1) |
|
Easy |
|
| 70 |
Climbing Stairs |
Solution |
O(n) |
O(n) |
|
Easy |
DP |
| 71 |
Simplify Path |
Solution |
O(n) |
O(n) |
|
Medium |
Stack |
| 72 |
Edit Distance |
Solution |
O(m*n) |
O(m+n) |
|
Hard |
|
| 73 |
Set Matrix Zeroes |
Solution |
O(mn) |
O(1) |
|
Medium |
|
| 74 |
Search a 2D Matrix |
Solution |
O(log(m*n)) |
O(1) |
|
Medium |
Binary Search |
| 75 |
Sort Colors |
Solution |
O(n) |
O(1) |
|
Medium |
Two Pointers |
| 76 |
Minimum Window Substring |
Solution |
O(n) |
O(k) |
|
Hard |
Two Pointers |
| 77 |
Combinations |
Solution |
O(n!) |
O(n) |
|
Medium |
Backtracking |
| 78 |
Subsets |
Solution |
O(n^2) |
O(1) |
|
Medium |
Backtracking |
| 79 |
Word Search |
Solution |
O((m*n)^2) |
O(m*n) |
|
Medium |
Backtracking, DFS |
| 80 |
Remove Duplicates from Sorted Array II |
Solution |
O(n) |
O(n) |
|
Medium |
|
| 81 |
Search in Rotated Sorted Array II |
Solution |
O(logn) |
O(1) |
|
Medium |
Binary Search |
| 82 |
Remove Duplicates from Sorted List II |
Solution |
O(n) |
O(1) |
|
Medium |
Linked List |
| 83 |
Remove Duplicates from Sorted List |
Solution |
O(n) |
O(1) |
|
Easy |
Linked List |
| 84 |
Largest Rectangle in Histogram |
Solution |
O(n) |
O(n) |
|
Hard |
Array, Stack |
| 85 |
Maximal Rectangle |
Solution |
O(m*n) |
O(n) |
|
Hard |
DP |
| 86 |
Partition List |
Solution |
O(n) |
O(1) |
|
Medium |
Linked List |
| 87 |
Scramble String |
Solution |
O(n^4) |
O(n^3 |
|
Hard |
Recursion |
| 88 |
Merge Sorted Array |
Solution |
O(max(m,n)) |
O(1) |
|
Easy |
|
| 89 |
Gray Code |
Solution |
O(n) |
O(1) |
|
Medium |
Bit Manipulation |
| 90 |
Subsets II |
Solution |
O(n^2) |
O(1) |
|
Medium |
Backtracking |
| 91 |
Decode Ways |
Solution |
O(n) |
O(n) |
|
Medium |
DP |
| 92 |
Reverse Linked List II |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 93 |
Restore IP Addresses |
Solution |
O(?) |
O(?) |
|
Medium |
Backtracking |
| 94 |
Binary Tree Inorder Traversal |
Solution |
O(n) |
O(h) |
|
Medium |
Binary Tree |
| 95 |
Unique Binary Search Trees II |
Solution |
O(?) |
O(?) |
|
Medium |
Recursion |
| 96 |
Unique Binary Search Trees |
Solution |
O(n^2) |
O(n) |
|
Medium |
Recursion, DP |
| 97 |
Interleaving String |
Solution |
O(?) |
O(?) |
|
Hard |
DP |
| 98 |
Validate Binary Search Tree |
Solution |
O(n) |
O(h) |
|
Medium |
DFS/Recursion |
| 99 |
Recover Binary Search Tree |
Solution |
O(?) |
O(?) |
|
Hard |
|
| 100 |
Same Tree |
Solution |
O(n) |
O(h) |
|
Easy |
DFS |
| 101 |
Symmetric Tree |
Solution |
O(n) |
O(h) |
|
Easy |
DFS |
| 102 |
Binary Tree Level Order Traversal |
Solution |
O(n) |
O(h) |
|
Medium |
BFS |
| 103 |
Binary Tree Zigzag Level Order Traversal |
Solution |
O(n) |
O(h) |
|
Medium |
BFS,DFS |
| 104 |
Maximum Depth of Binary Tree |
Solution |
O(n) |
O(h) |
|
Easy |
DFS |
| 105 |
Construct Binary Tree from Preorder and Inorder Traversal |
Solution |
O(n) |
O(n) |
|
Medium |
Recursion, Tree |
| 106 |
Construct Binary Tree from Inorder and Postorder Traversal |
Solution |
O(n) |
O(n) |
|
Medium |
Recursion, Tree |
| 107 |
Binary Tree Level Order Traversal II |
Solution |
O(nlogn) |
O(h) |
|
Easy |
BFS |
| 108 |
Convert Sorted Array to Binary Search Tree |
Solution |
O(n) |
O(h) |
|
Easy |
Tree |
| 109 |
Convert Sorted List to Binary Search Tree |
Solution |
O(n) |
O(h) |
|
Medium |
DFS, Recursion |
| 110 |
Balanced Binary Tree |
Solution |
O(n) |
O(1)~O(h) |
|
Easy |
DFS |
| 111 |
Minimum Depth of Binary Tree |
Solution |
O(n) |
O(1)~O(h) |
|
Easy |
BFS, DFS |
| 112 |
Path Sum |
Solution |
O(n) |
O(1) |
|
Easy |
DFS |
| 113 |
Path Sum II |
Solution |
O(n) |
O(h) |
|
Medium |
DFS, Backtracking |
| 114 |
Flatten Binary Tree to Linked List |
Solution |
O(n) |
O(h) |
|
Medium |
Tree |
| 115 |
Distinct Subsequences |
Solution |
O(m*n) |
O(m*n) |
|
Hard |
DP |
| 116 |
Populating Next Right Pointers in Each Node |
Solution |
O(n) |
O(1) |
|
Medium |
BFS |
| 117 |
Populating Next Right Pointers in Each Node II |
Solution |
O(n) |
O(1) |
|
Medium |
BFS |
| 118 |
Pascal's Triangle |
Solution |
O(n^2) |
O(1) |
|
Easy |
|
| 119 |
Pascal's Triangle II |
Solution |
O(n^2) |
O(k) |
|
Easy |
|
| 120 |
Triangle |
Solution |
O(m*n) |
O(n) |
|
Medium |
DP |
| 121 |
Best Time to Buy and Sell Stock |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 122 |
Best Time to Buy and Sell Stock II |
Solution |
O(n) |
O(1) |
|
Easy |
Greedy |
| 123 |
Best Time to Buy and Sell Stock III |
Solution |
O(n) |
O(1) |
|
Hard |
DP |
| 124 |
Binary Tree Maximum Path Sum |
Solution |
O(n) |
O(h) |
|
Hard |
Tree, DFS |
| 125 |
Valid Palindrome |
Solution |
O(n) |
O(1) |
|
Easy |
Two Pointers |
| 126 |
Word Ladder II |
Solution |
O(?) |
O(?) |
|
Hard |
BFS |
| 127 |
Word Ladder |
Solution |
O(n^2) |
O(n) |
|
Medium |
BFS |
| 128 |
Longest Consecutive Sequence |
Solution |
O(n) |
O(n) |
|
Hard |
Union Find |
| 129 |
Sum Root to Leaf Numbers |
Solution |
O(n) |
O(h) |
|
Medium |
DFS |
| 130 |
Surrounded Regions |
Solution |
O(?) |
O(?) |
|
Medium |
|
| 131 |
Palindrome Partitioning |
Solution |
O(n^2) |
O(n^2) |
|
Medium |
|
| 132 |
Palindrome Partitioning II |
Solution |
O(n^2) |
O(n^2) |
|
Hard |
|
| 133 |
Clone Graph |
Solution |
O(n) |
O(n) |
|
Medium |
HashMap, BFS, Graph |
| 134 |
Gas Station |
Solution |
O(n) |
O(1) |
|
Medium |
Greedy |
| 135 |
Candy |
Solution |
O(n) |
O(1) |
|
Hard |
Greedy |
| 136 |
Single Number |
Solution |
O(n) |
O(1) |
|
Easy |
Bit Manipulation |
| 137 |
Single Number II |
Solution |
O(n) |
O(1) |
|
Medium |
Bit Manipulation |
| 138 |
Copy List with Random Pointer |
Solution |
O(n) |
O(n) |
|
Medium |
LinkedList, HashMap |
| 139 |
Word Break |
Solution |
O(n^2) |
O(n) |
|
Medium |
DP, Pruning |
| 140 |
Word Break II |
Solution |
? |
O(n^2) |
|
Hard |
Backtracking/DFS |
| 141 |
Linked List Cycle |
Solution |
O(n) |
O(1) |
|
Easy |
Linked List |
| 142 |
Linked List Cycle II |
Solution |
O(n) |
O(1) |
|
Medium |
Linked List |
| 143 |
Reorder List |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 144 |
Binary Tree Preorder Traversal |
Solution |
O(n) |
O(h) |
|
Medium |
Binary Tree |
| 145 |
Binary Tree Postorder Traversal |
Solution |
O(n) |
O(h) |
|
Hard |
Binary Tree |
| 146 |
LRU Cache |
Solution |
amortized O(1) |
O(k) |
|
Hard |
Doubly Linked List, LinkedHashMap |
| 147 |
Insertion Sort List |
Solution |
O(n^2) |
O(1) |
|
Medium |
Linked List |
| 148 |
Sort List |
Solution |
O(nlogn) |
O(h) |
|
Medium |
Linked List, Sort |
| 149 |
Max Points on a Line |
Solution |
O(?) |
O(?) |
|
Hard |
|
| 150 |
Evaluate Reverse Polish Notation |
Solution |
O(?) |
O(?) |
|
Medium |
|
| 151 |
Reverse Words in a String |
Solution |
O(n) |
O(n) |
|
Medium |
String |
| 152 |
Maximum Product Subarray |
Solution |
O(n) |
O(1) |
|
Medium |
Array |
| 153 |
Find Minimum in Rotated Sorted Array |
Solution |
O(logn) |
O(1) |
|
Medium |
Array, Binary Search |
| 154 |
Find Minimum in Rotated Sorted Array II |
Solution |
O(logn) |
O(1) |
|
Hard |
Array, Binary Search |
| 155 |
Min Stack |
Solution |
O(1) |
O(n) |
|
Easy |
Stack |
| 156 |
Binary Tree Upside Down |
Solution |
O(n) |
O(h) |
|
Medium |
Tree, Recursion |
| 157 |
Read N Characters Given Read4 |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 158 |
Read N Characters Given Read4 II - Call multiple times |
Solution |
O(n) |
O(1) |
|
Hard |
|
| 159 |
Longest Substring with At Most Two Distinct Characters |
Solution |
O(n) |
O(1) |
|
Hard |
String, Sliding Window |
| 160 |
Intersection of Two Linked Lists |
Solution |
O(m+n) |
O(1) |
|
Easy |
Linked List |
| 161 |
One Edit Distance |
Solution |
O(n) |
O(1) |
|
|
|
| 162 |
Find Peak Element |
Solution |
O(1) |
O(logn)/O(n) |
|
Binary Search |
|
| 163 |
Missing Ranges |
Solution |
O(n) |
O(1) |
|
|
|
| 164 |
Maximum Gap |
Solution |
O(n) |
O(n) |
|
Hard |
|
| 165 |
Compare Version Numbers |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 166 |
Fraction to Recurring Decimal |
Solution |
O(1) |
O(1) |
|
Medium |
HashMap |
| 167 |
Two Sum II - Input array is sorted |
Solution |
O(n) |
O(1) |
|
Easy |
Binary Search |
| 168 |
Excel Sheet Column Title |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 169 |
Majority Element |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 170 |
Two Sum III - Data structure design |
Solution |
O(n) |
O(n) |
|
Easy |
|
| 171 |
Excel Sheet Column Number |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 172 |
Factorial Trailing Zeroes |
Solution |
O(logn) |
O(1) |
|
Easy |
|
| 173 |
Binary Search Tree Iterator |
Solution |
O(1) |
O(h) |
|
Medium |
Stack, Design |
| 174 |
Dungeon Game |
QueueStack |
O(m*n) |
O(m*n) |
|
Hard |
DP |
| 179 |
Largest Number |
Solution |
O(?) |
O(?) |
|
Medium |
|
| 186 |
Reverse Words in a String II |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 187 |
Repeated DNA Sequences |
Solution |
O(n) |
O(n) |
|
Medium |
|
| 188 |
Best Time to Buy and Sell Stock IV |
Solution |
O(n*k) |
O(n*k) |
|
Hard |
DP |
| 189 |
Rotate Array |
Solution |
O(n) |
O(n), could be optimized to O(1) |
|
Easy |
|
| 190 |
Reverse Bits |
Solution |
O(n) |
O(1) |
|
Easy |
Bit Manipulation |
| 191 |
Number of 1 Bits |
Solution |
O(1) |
O(1) |
|
Easy |
Bit Manipulation |
| 198 |
House Robber |
Solution |
O(n) |
O(n) |
|
Easy |
DP |
| 199 |
Binary Tree Right Side View |
Solution |
O(n) |
O(h) |
|
Medium |
BFS |
| 200 |
Number of Islands |
Solution |
O(m*n) |
O(m*n) |
|
Medium |
Union Find, DFS |
| 201 |
Bitwise AND of Numbers Range |
Solution |
O(min(m,n)) |
O(1) |
|
Medium |
Bit Manipulation |
| 202 |
Happy Number |
Solution |
O(k) |
O(k) |
|
Easy |
|
| 203 |
Remove Linked List Elements |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 204 |
Count Primes |
Solution |
O(nloglogn) |
O(n) |
|
Easy |
The Sieve of Eratosthenes |
| 205 |
Isomorphic Strings |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 206 |
Reverse Linked List |
Solution |
O(n) |
O(1) |
|
Easy |
Linked List |
| 207 |
Course Schedule |
Solution |
O(?) |
O(?) |
|
Medium |
|
| 208 |
Implement Trie |
Solution |
O(n) |
O(1) |
|
Medium |
Trie |
| 209 |
Minimum Size Subarray Sum |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 210 |
Course Schedule II |
Solution |
O(?) |
O(?) |
|
Medium |
|
| 211 |
Add and Search Word - Data structure design |
Solution |
O(n) |
O(h) |
|
Medium |
Trie |
| 212 |
Word Search II |
Solution |
O(mnl) |
O(l) |
|
Hard |
Trie |
| 213 |
House Robber II |
Solution |
O(n) |
O(n) |
|
Medium |
DP |
| 214 |
Shortest Palindrome |
Solution |
O(?) |
O(?) |
|
Hard |
KMP |
| 215 |
Kth Largest Element in an Array |
Solution |
O(nlogn) |
O(n) |
|
Medium |
Heap |
| 216 |
Combination Sum III |
Solution |
O(k * C(n, k)) |
O(k) |
|
Medium |
Backtracking |
| 217 |
Contains Duplicate |
Solution |
O(n) |
O(n) |
|
Easy |
HashSet |
| 218 |
The Skyline Problem |
Solution |
O(n) |
O(n) |
|
Hard |
TreeMap, Design |
| 219 |
Contains Duplicate II |
Solution |
O(n) |
O(n) |
|
Easy |
HashMap |
| 220 |
Contains Duplicate III |
Solution |
O(nlogn) |
O(n) |
|
Medium |
TreeSet |
| 221 |
Maximal Square |
Solution |
O(?) |
O(h) |
|
Medium |
Recursion |
| 222 |
Count Complete Tree Nodes |
Solution |
O(?) |
O(h) |
|
Medium |
Recursion |
| 223 |
Rectangle Area |
Solution |
O(1) |
O(1) |
|
Easy |
|
| 224 |
Basic Calculator |
Solution |
? |
? |
|
Hard |
|
| 225 |
Implement Stack using Queues |
Solution |
O(n) |
O(n) |
|
Easy |
Stack, Queue |
| 226 |
Invert Binary Tree |
Solution |
O(n) |
O(h) |
|
Easy |
DFS, recursion |
| 227 |
Basic Calculator II |
Solution |
O(n) |
O(n) |
|
Medium |
String |
| 228 |
Summary Ranges |
Solution |
O(n) |
O(1) |
|
Medium |
Array |
| 229 |
Majority Element II |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 230 |
Kth Smallest Element in a BST |
Solution |
O(n) |
O(k) |
|
Medium |
Tree |
| 231 |
Power of Two |
Solution |
O(1) |
O(1) |
|
Easy |
|
| 232 |
Implement Queue using Stacks |
Solution |
O(n) |
O(n) |
|
Medium |
Stack, Design |
| 233 |
Number of Digit One |
Solution |
O(n) |
O(1) |
|
Hard |
Math |
| 234 |
Palindrome Linked List |
Solution |
O(n) |
O(1) |
|
Easy |
Linked List |
| 235 |
Lowest Common Ancestor of a Binary Search Tree |
Solution |
O(h) |
O(1) |
|
Easy |
DFS |
| 236 |
Lowest Common Ancestor of a Binary Tree |
Solution |
O(n) |
O(h) |
|
Medium |
DFS |
| 237 |
Delete Node in a Linked List |
Solution |
O(1) |
O(1) |
|
Easy |
LinkedList |
| 238 |
Product of Array Except Self |
Solution |
O(n) |
O(1) |
|
Medium |
Array |
| 239 |
Sliding Window Maximum |
Solution |
O(nlogn) |
O(k) |
|
Hard |
Heap |
| 240 |
Search a 2D Matrix II |
Solution |
O(m+n) |
O(1) |
|
Medium |
Binary Search |
| 241 |
Different Ways to Add Parentheses |
Solution |
O(O(n * 4^n / n^(3/2))) |
O(n * 4^n / n^(3/2)) |
|
Medium |
Divide and Conquer |
| 242 |
Valid Anagram |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 243 |
Shortest Word Distance |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 244 |
Shortest Word Distance II |
Solution |
O(n) |
O(n) |
|
Medium |
HashMap |
| 245 |
Shortest Word Distance III |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 246 |
Strobogrammatic Number |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 247 |
Strobogrammatic Number II |
Solution |
O(n^2) |
O(n) |
|
Medium |
Recursion |
| 248 |
Strobogrammatic Number III |
Solution |
O(?) |
O(?) |
|
Hard |
Recursion, DFS |
| 249 |
Group Shifted Strings |
Solution |
O(nlogn) |
O(n) |
|
|
|
| 250 |
Count Univalue Subtrees |
Solution |
O(n) |
O(h) |
|
Medium |
DFS |
| 251 |
Flatten 2D Vector |
Solution |
O(1) |
O(m*n) |
|
Medium |
|
| 252 |
Meeting Rooms |
Solution |
O(nlogn) |
O(1) |
|
Easy |
|
| 253 |
Meeting Rooms II |
Solution |
O(nlogn) |
O(h) |
|
Medium |
Heap |
| 254 |
Factor Combinations |
Solution |
O(nlogn) |
O(nlogn) |
|
Medium |
Backtracking |
| 255 |
Verify Preorder Sequence in Binary Search Tree |
Solution |
O(n) |
O(h) |
|
Medium |
Tree |
| 256 |
Paint House |
Solution |
O(n) |
O(1) |
|
Medium |
DP |
| 257 |
Binary Tree Paths |
Solution |
O(n*h) |
O(h) |
|
|
DFS/Recursion |
| 258 |
Add Digits |
Solution |
O(1) |
O(1) |
|
Easy |
|
| 259 |
3Sum Smaller |
Solution |
O(n^2) |
O(1) |
|
Medium |
|
| 260 |
Single Number III |
Solution |
O(n) |
O(n) |
|
Medium |
|
| 261 |
Graph Valid Tree |
Solution |
O(V+E) |
O(V+E) |
|
Medium |
|
| 263 |
Ugly Number |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 264 |
Ugly Number II |
Solution |
O(n) |
O(n) |
|
Medium |
DP |
| 265 |
Paint House II |
Solution |
O(n*k) |
O(1) |
|
Hard |
DP |
| 266 |
Palindrome Permutation |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 267 |
Palindrome Permutation II |
Solution |
O(n*n!) |
O(n) |
|
Medium |
|
| 268 |
Missing Number |
Solution |
O(n) |
O(1) |
|
Easy |
Bit Manipulation |
| 269 |
Alien Dictionary |
Solution |
O(?) |
O(?) |
|
Hard |
Topological Sort |
| 270 |
Closest Binary Search Tree Value |
Solution |
O(h) |
O(1) |
|
Easy |
DFS |
| 271 |
Encode and Decode Strings |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 272 |
Closest Binary Search Tree Value II |
Solution |
O(h+k) |
O(h) |
|
Hard |
Stack |
| 273 |
Integer to English Words |
Solution |
O(n) |
O(1) |
|
Hard |
Math, String |
| 274 |
H-Index |
Solution |
O(nlogn) |
O(1) |
|
Medium |
|
| 275 |
H-Index II |
Solution |
O(logn) |
O(1) |
|
Medium |
Binary Search |
| 276 |
Paint Fence |
Solution |
O(n) |
O(1) |
|
Easy |
DP |
| 277 |
Find the Celebrity |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 278 |
First Bad Version |
Solution |
O(logn) |
O(1) |
|
Easy |
Binary Search |
| 279 |
Perfect Squares |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 280 |
Wiggle Sort |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 281 |
Zigzag Iterator |
Solution |
O(1) |
O(k) |
|
Medium |
|
| 282 |
Expression Add Operators |
Solution |
O(?) |
O(?) |
|
Hard |
|
| 283 |
Move Zeroes |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 284 |
Peeking Iterator |
Solution |
O(n) |
O(n) |
|
Medium |
Design |
| 285 |
Inorder Successor In BST |
Solution |
O(h) |
O(1) |
|
Medium |
Tree |
| 286 |
Walls and Gates |
Solution |
O(m*n) |
O(g) |
|
Medium |
BFS |
| 287 |
Find the Duplicate Number |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 288 |
Unique Word Abbreviation |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 289 |
Game of Life |
Solution |
O(m*n) |
O(m*n), could be optimized to O(1) |
|
Medium |
|
| 290 |
Word Pattern |
Solution |
O(n) |
O(n) |
|
Easy |
HashMap |
| 291 |
Word Pattern II |
Solution |
O(n) |
O(n) |
|
Hard |
Recursion, Backtracking |
| 292 |
Nim Game |
Solution |
O(1) |
O(1) |
|
Easy |
|
| 293 |
Flip Game |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 294 |
Flip Game II |
Solution |
O(?) |
O(?) |
|
Medium |
Backtracking |
| 295 |
Find Median from Data Stream |
Solution |
O(logn) |
O(n) |
|
Hard |
Heap |
| 296 |
Best Meeting Point |
Solution |
? |
? |
|
Hard |
|
| 297 |
Serialize and Deserialize Binary Tree |
Solution |
O(n) |
O(h) |
|
Hard |
BFS |
| 298 |
Binary Tree Longest Consecutive Sequence |
Solution |
O(n) |
O(n) |
|
Medium |
Tree |
| 299 |
Bulls and Cows |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 300 |
Longest Increasing Subsequence |
Solution |
O(logn) |
O(n) |
|
Medium |
DP |
| 301 |
Remove Invalid Parentheses |
Solution |
? |
? |
|
Hard |
BFS |
| 302 |
Smallest Rectangle Enclosing Black Pixels |
Solution |
? |
O(m*n) |
|
Hard |
DFS, BFS |
| 303 |
Range Sum Query - Immutable |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 304 |
Range Sum Query 2D - Immutable |
Solution |
? |
? |
|
Medium |
|
| 305 |
Number of Islands II |
Solution |
? |
? |
|
Hard |
Union Find |
| 306 |
Additive Number |
Solution |
O(n^2) |
O(n) |
|
Medium |
|
| 307 |
Range Sum Query - Mutable |
Solution |
? |
? |
|
Medium |
Tree |
| 308 |
Range Sum Query 2D - Mutable |
Solution |
? |
? |
|
Hard |
Tree |
| 309 |
Best Time to Buy and Sell Stock with Cooldown |
Solution |
O(n) |
O(1) |
|
Medium |
DP |
| 310 |
Minimum Height Trees |
Solution |
? |
? |
|
Medium |
|
| 311 |
Sparse Matrix Multiplication |
Solution |
O(mnl) |
O(m*l) |
|
Medium |
|
| 312 |
Burst Balloons |
Solution |
O(?) |
O(?) |
|
Hard |
DP |
| 313 |
Super Ugly Number |
Solution |
O(?) |
O(?) |
|
Medium |
|
| 314 |
Binary Tree Vertical Order Traversal |
Solution |
O(n) |
O(n) |
|
Medium |
HashMap, BFS |
| 315 |
Count of Smaller Numbers After Self |
Solution |
O(?) |
O(?) |
|
Hard |
Tree |
| 316 |
Remove Duplicate Letters |
Solution |
O(n) |
O(1) |
|
Hard |
Stack, Recursion, Greedy |
| 317 |
Shortest Distance from All Buildings |
Solution |
O(?) |
O(?) |
|
Hard |
|
| 318 |
Maximum Product of Word Lengths |
Solution |
O(n^2) |
O(n) |
|
Medium |
|
| 319 |
Bulb Switcher |
Solution |
O(1) |
O(1) |
|
Medium |
Brainteaser |
| 320 |
Generalized Abbreviation |
Solution |
O(n*2^n) |
O(n) |
|
Medium |
Backtracking, Bit Manipulation |
| 321 |
Create Maximum Number |
Solution |
O(?) |
O(?) |
|
Hard |
|
| 322 |
Coin Change |
Solution |
O(n*k) |
O(k) |
|
Medium |
DP |
| 323 |
Number of Connected Components in an Undirected Graph |
Solution |
O(?) |
O(?) |
|
Medium |
|
| 324 |
Wiggle Sort II |
Solution |
O(n) |
O(n) |
|
Medium |
Sort |
| 325 |
Maximum Size Subarray Sum Equals k |
Solution |
O(n) |
O(n) |
|
Medium |
HashTable |
| 326 |
Power of Three |
Solution |
O(1) |
O(1) |
|
Easy |
Math |
| 327 |
Count of Range Sum |
Solution |
O(nlogn) |
O(n) |
|
Hard |
BST, Divide and Conquer |
| 328 |
Odd Even Linked List |
Solution |
O(n) |
O(1) |
|
Medium |
Linked List |
| 329 |
Longest Increasing Path in a Matrix |
Solution |
O(m*n) |
O(m*n) |
|
Hard |
DFS, DP |
| 330 |
Patching Array |
Solution |
O(m+logn) |
O(1) |
|
Hard |
Greedy |
| 331 |
Verify Preorder Serialization of a Binary Tree |
Solution |
O(n) |
O(n) |
|
Medium |
Stack |
| 332 |
Reconstruct Itinerary |
Solution |
O(n) |
O(n) |
|
Medium |
Graph, DFS |
| 333 |
Largest BST Subtree |
Solution |
O(n) |
O(n) |
|
Medium |
Tree |
| 334 |
Increasing Triplet Subsequence |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 335 |
Self Crossing |
Solution |
O(n) |
O(1) |
|
Hard |
Math |
| 336 |
Palindrome Pairs |
Solution |
O(n^2) |
O(n) |
|
Hard |
|
| 337 |
House Robber III |
Solution |
O(n) |
O(n) |
|
Medium |
DP |
| 338 |
Counting Bits |
Solution |
O(nlogn) |
O(h) |
|
Medium |
|
| 339 |
Nested List Weight Sum |
Solution |
O(n) |
O(h)) |
|
Easy |
DFS |
| 340 |
Longest Substring with At Most K Distinct Characters |
Solution |
O(n) |
O(1) |
|
Hard |
Sliding Window |
| 341 |
Flatten Nested List Iterator |
Solution |
O(n) |
O(n) |
|
Medium |
Stack |
| 342 |
Power of Four |
Solution |
O(n) |
O(1) |
|
Easy |
Math |
| 343 |
Integer Break |
Solution |
O(1) |
O(1) |
|
Medium |
Math |
| 344 |
Reverse String |
Solution |
O(n) |
O(1) |
|
Easy |
String |
| 345 |
Reverse Vowels of a String |
Solution |
O(n) |
O(1) |
|
Easy |
String |
| 346 |
Moving Average from Data Stream |
Solution |
O(1) |
O(w)) |
|
Easy |
Queue |
| 347 |
Top K Frequent Elements |
Solution |
O(n) |
O(k) k is is the number of unique elements in the given array |
|
Medium |
HashTable, Heap, Bucket Sort |
| 348 |
Design Tic-Tac-Toe |
Solution |
O(1) |
O(n) |
|
Medium |
Design |
| 349 |
Intersection of Two Arrays |
Solution |
O(m+n) |
O(min(m,n)) |
|
Easy |
Two Pointers, Binary Search |
| 350 |
Intersection of Two Arrays II |
Solution |
O(m+n) |
O((m+n)) could be optimized |
|
Easy |
HashMap, Binary Search |
| 351 |
Android Unlock Patterns |
Solution |
O(?) |
O(?) |
|
Medium |
|
| 352 |
Data Stream as Disjoint Intervals |
Solution |
O(logn) |
O(n) |
|
Hard |
TreeMap |
| 353 |
Design Snake Game |
Solution |
O(?) |
O(?) |
|
Medium |
|
| 354 |
Russian Doll Envelopes |
Solution |
O(nlogn) |
O(1) |
|
Hard |
DP, Binary Search |
| 355 |
Design Twitter |
Solution |
O(n) |
O(n) |
|
Medium |
Design, HashMap, Heap |
| 356 |
Line Reflection |
Solution |
O(n) |
O(n) |
|
Medium |
HashSet |
| 357 |
Count Numbers with Unique Digits |
Solution |
O(n) |
O(1) |
|
Medium |
DP, Math |
| 358 |
Rearrange String k Distance Apart |
Solution |
O(n) |
O(n) |
|
Hard |
HashMap, Heap, Greedy |
| 359 |
Logger Rate Limiter |
Solution |
amortized O(1) |
O(k) |
|
Easy |
HashMap |
| 360 |
Sort Transformed Array |
Solution |
O(n) |
O(1) |
|
Medium |
Two Pointers, Math |
| 361 |
Bomb Enemy |
Solution |
O(?) |
O(?) |
|
Medium |
|
| 362 |
Design Hit Counter |
Solution |
O(1) amortized |
O(k) |
|
Medium |
Design |
| 363 |
Max Sum of Rectangle No Larger Than K |
Solution |
|
|
|
Hard |
DP |
| 364 |
Nested List Weight Sum II |
Solution |
O(n) |
O(h) |
|
Medium |
DFS |
| 365 |
Water and Jug Problem |
Solution |
O(n) |
O(1) |
|
Medium |
Math |
| 366 |
Find Leaves of Binary Tree |
Solution |
O(n) |
O(h) |
|
Medium |
DFS |
| 367 |
Valid Perfect Square |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 368 |
Largest Divisible Subset |
Solution |
O(n^2) |
O(n) |
|
Medium |
DP |
| 369 |
Plus One Linked List |
Solution |
O(n) |
O(1) |
|
Medium |
Linked List |
| 370 |
Range Addition |
Solution |
O(n+k) |
O(1) |
|
Medium |
Array |
| 371 |
Sum of Two Integers |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 372 |
Super Pow |
Solution |
O(n) |
O(1) |
|
Medium |
Math |
| 373 |
Find K Pairs with Smallest Sums |
Solution |
O(klogk) |
O(k) |
|
Medium |
Heap |
| 374 |
Guess Number Higher or Lower |
Solution |
O(logn) |
O(1) |
|
Easy |
Binary Search |
| 375 |
Guess Number Higher or Lower II |
Solution |
O(n^2) |
O(n^2) |
|
Medium |
DP |
| 376 |
Wiggle Subsequence |
Solution |
O(n) |
O(1) |
|
Medium |
DP, Greedy |
| 377 |
Combination Sum IV |
Solution |
O(n^2) |
O(n) |
|
Medium |
DP |
| 378 |
Kth Smallest Element in a Sorted Matrix |
Solution |
O(logm*n) |
O(1) |
|
Medium |
Binary Search |
| 379 |
Design Phone Directory |
Solution |
O(1) |
O(n) |
|
Medium |
|
| 380 |
Insert Delete GetRandom O(1) |
Solution |
O(n) |
O(1) |
|
Medium |
Design, HashMap |
| 381 |
Insert Delete GetRandom O(1) - Duplicates allowed |
Solution |
|
|
|
Hard |
|
| 382 |
Linked List Random Node |
Solution |
O(1) |
O(n) |
|
Medium |
Reservoir Sampling |
| 383 |
Ransom Note |
Solution |
O(n) |
O(n) |
|
Easy |
String |
| 384 |
Shuffle an Array |
Solution |
O(n) |
O(n) |
|
Medium |
|
| 385 |
Mini Parser |
Solution |
O(n) |
O(h) |
|
Medium |
Stack |
| 386 |
Lexicographical Numbers |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 387 |
First Unique Character in a String |
Solution |
O(n) |
O(n) |
|
Easy |
HashMap |
| 388 |
Longest Absolute File Path |
Solution |
O(n) |
O(d) |
|
Medium |
Stack |
| 389 |
Find the Difference |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 390 |
Elimination Game |
Solution |
O(logn) |
O(1) |
|
Medium |
|
| 391 |
Perfect Rectangle |
Solution |
O(n) |
O(1) |
|
Hard |
|
| 392 |
Is Subsequence |
Solution |
O(m*n) |
O(1) |
|
Medium |
Array, String |
| 393 |
UTF-8 Validation |
Solution |
O(?) |
O(?) |
|
Medium |
Bit Manipulation |
| 395 |
Longest Substring with At Least K Repeating Characters |
Solution |
O(n^2) |
O(1) |
|
Medium |
Recursion |
| 396 |
Rotate Function |
Solution |
O(n^2) could be optimized to O(n) |
O(1) |
|
Easy |
|
| 397 |
Integer Replacement |
Solution |
? |
? |
|
Easy |
BFS |
| 398 |
Random Pick Index |
Solution |
|
|
|
Medium |
Reservoir Sampling |
| 399 |
Evaluate Division |
Solution |
O(n*n!) |
O(n) |
|
Medium |
Graph, DFS, Backtracking |
| 400 |
Nth Digit |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 401 |
Binary Watch |
Solution |
O(1) |
O(1) |
|
Easy |
|
| 402 |
Remove K Digits |
Solution |
O(n) |
O(n) |
|
Medium |
Greedy, Stack |
| 403 |
Frog Jump |
Solution |
O(n^2) |
O(n^2) |
|
Hard |
DP |
| 404 |
Sum of Left Leaves |
Solution |
O(n) |
O(h) |
|
Easy |
|
| 405 |
Convert a Number to Hexadecimal |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 406 |
Queue Reconstruction by Height |
Solution |
O(nlogn) |
O(1) |
|
Medium |
LinkedList, PriorityQueue |
| 407 |
Trapping Rain Water II |
Solution |
|
|
|
Hard |
Heap |
| 408 |
Valid Word Abbreviation |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 410 |
Split Array Largest Sum |
Solution |
O(nlogn) |
O(1) |
|
Hard |
Binary Search, DP |
| 411 |
Minimum Unique Word Abbreviation |
Solution |
O(?) |
O(?) |
|
Hard |
NP-Hard, Backtracking, Trie, Recursion |
| 412 |
Fizz Buzz |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 413 |
Arithmetic Slices |
Solution |
O(n) |
O(1) |
|
Medium |
DP |
| 414 |
Third Maximum Number |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 415 |
Add Strings |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 416 |
Partition Equal Subset Sum |
Solution |
O(m*n) |
O(m*n) |
|
Medium |
DP |
| 417 |
Pacific Atlantic Water Flow |
Solution |
O(mnMax(m,n)) |
O(m*n) |
|
Medium |
DFS |
| 418 |
Sentence Screen Fitting |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 419 |
Battleships in a Board |
Solution |
O(m*n) |
O(1) |
|
Medium |
DFS |
| 420 |
Strong Password Checker |
Solution |
? |
? |
|
Hard |
|
| 421 |
Maximum XOR of Two Numbers in an Array |
Solution |
O(n) |
O(1) |
|
Medium |
Bit Manipulation, Trie |
| 422 |
Valid Word Square |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 423 |
Reconstruct Original Digits from English |
Solution |
O(n) |
O(1) |
|
Medium |
Math |
| 424 |
Longest Repeating Character Replacement |
Solution |
O(n) |
O(1) |
|
Medium |
Sliding Window |
| 425 |
Word Squares |
Solution |
O(n!) |
O(n) |
|
Hard |
Trie, Backtracking, Recursion |
| 432 |
All O`one Data Structure |
Solution |
O(1) |
O(n) |
|
Hard |
Design |
| 434 |
Number of Segments in a String |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 435 |
Non-overlapping Intervals |
Solution |
O(nlogn) |
O(1) |
|
Medium |
Greedy |
| 436 |
Find Right Interval |
Solution |
O(nlogn) |
O(n) |
|
Medium |
Binary Search |
| 437 |
Path Sum III |
Solution |
O(n^2) |
O(n) |
|
Easy |
DFS, recursion |
| 438 |
Find All Anagrams in a String |
Solution |
O(n) |
O(1) |
|
Easy |
Sliding Window |
| 439 |
Ternary Expression Parser |
Solution |
O(n) |
O(n) |
|
Medium |
Stack |
| 440 |
K-th Smallest in Lexicographical Order |
Solution |
O(n^2) |
O(1) |
|
Hard |
|
| 441 |
Arranging Coins |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 442 |
Find All Duplicates in an Array |
Solution |
O(n) |
O(1) |
|
Medium |
Array |
| 443 |
String Compression |
Solution |
O(n) |
O(n) |
|
Easy |
|
| 444 |
Sequence Reconstruction |
Solution |
O(n) |
O(n) |
|
Medium |
Topological Sort, Graph |
| 445 |
Add Two Numbers II |
Solution |
O(max(m,n) |
O(max(m,n)) |
|
Medium |
Stack, LinkedList |
| 446 |
Arithmetic Slices II - Subsequence |
Solution |
O(n^2) |
O(n^2) |
|
Hard |
DP |
| 447 |
Number of Boomerangs |
Solution |
O(n^2) |
O(n) |
|
Easy |
HashMap |
| 448 |
Find All Numbers Disappeared in an Array |
Solution |
O(n) |
O(1) |
|
Easy |
Array, HashMap |
| 449 |
Serialize and Deserialize BST |
Solution |
O(n) |
O(h) |
|
Medium |
BFS |
| 450 |
Delete Node in a BST |
Solution |
O(?) |
O(?) |
|
Medium |
Tree, Recursion |
| 451 |
Sort Characters By Frequency |
Solution |
O(nlogn) |
O(n) |
|
Medium |
HashMap |
| 452 |
Minimum Number of Arrows to Burst Balloons |
Solution |
O(nlogn) |
O(1) |
|
Medium |
Array, Greedy |
| 453 |
Minimum Moves to Equal Array Elements |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 454 |
4Sum II |
Solution |
O(n) |
O(n) |
|
Medium |
HashMap |
| 455 |
Assign Cookies |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 456 |
132 Pattern |
Solution |
O(n) |
O(n) |
|
Medium |
Stack |
| 457 |
Circular Array Loop |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 458 |
Poor Pigs |
Solution |
O(1) |
O(1) |
|
Easy |
Math |
| 459 |
Repeated Substring Pattern |
Solution |
O(n) |
O(n) |
|
Easy |
String, KMP |
| 460 |
LFU Cache |
Solution |
O(1) |
O(n) |
|
Hard |
Design, LinkedHashMap, HashMap |
| 461 |
Hamming Distance |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 462 |
Minimum Moves to Equal Array Elements II |
Solution |
O(nlogn) |
O(1) |
|
Medium |
|
| 463 |
Island Perimeter |
Solution |
O(m*n) |
O(1) |
|
Easy |
|
| 464 |
Can I Win |
Solution |
O(2^n) |
O(n) |
|
Medium |
DP |
| 465 |
Optimal Account Balancing |
Solution |
|
|
|
Hard |
DP |
| 466 |
Count The Repetitions |
Solution |
O(max(m,n)) |
O(1) |
|
Hard |
DP |
| 467 |
Unique Substrings in Wraparound String |
Solution |
O(n) |
O(1) |
|
Medium |
DP |
| 468 |
Validate IP Address |
Solution |
O(n) |
O(1) |
|
Medium |
String |
| 469 |
Convex Polygon |
Solution |
O(n) |
O(1) |
|
Medium |
Math |
| 471 |
Encode String with Shortest Length |
Solution |
O(n^3) |
O(n^2) |
|
Hard |
DP |
| 472 |
Concatenated Words |
Solution |
O(n^2) |
O(n) |
|
Hard |
Trie, DP, DFS |
| 473 |
Matchsticks to Square |
Solution |
O(n!) |
O(n) |
|
Medium |
Backtracking, DFS |
| 474 |
Ones and Zeroes |
Solution |
O(n) |
O(m*n) |
|
Medium |
DP |
| 475 |
Heaters |
Solution |
max(O(nlogn), O(mlogn)) - m is the length of houses, n is the length of heaters |
O(1) |
|
Easy |
Array Binary Search |
| 476 |
Number Complement |
Solution |
O(n) |
O(1) |
|
Easy |
Bit Manipulation |
| 477 |
Total Hamming Distance |
Solution |
O(n) |
O(1) |
|
Medium |
Bit Manipulation |
| 479 |
Largest Palindrome Product |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 480 |
Sliding Window Median |
Solution |
O(nlogk) |
O(k) |
|
Hard |
Heap |
| 481 |
Magical String |
Solution |
O(?) |
O(?) |
|
Medium |
|
| 482 |
License Key Formatting |
Solution |
O(n) |
O(n) |
|
Medium |
|
| 483 |
Smallest Good Base |
Solution |
O(logn) |
O(1) |
|
Hard |
Binary Search, Math |
| 484 |
Find Permutation |
Solution |
O(n) |
O(1) |
|
Medium |
Array, String, Greedy |
| 485 |
Max Consecutive Ones |
Solution |
O(n) |
O(1) |
|
Easy |
Array |
| 486 |
Predict the Winner |
Solution |
O(2^n) |
O(n^2) |
|
Medium |
DP |
| 487 |
Max Consecutive Ones II |
Solution |
O(n) |
O(n) |
|
Medium |
Array |
| 488 |
Zuma Game |
Solution |
O(?) |
O(?) |
|
Hard |
DFS, Backtracking |
| 490 |
The Maze |
Solution |
O(m*n) |
O(m*n) |
|
Medium |
BFS |
| 491 |
Increasing Subsequences |
Solution |
O(n!) |
O(n) |
|
Medium |
Backtracking, DFS |
| 492 |
Construct the Rectangle |
Solution |
O(n) |
O(1) |
|
Easy |
Array |
| 493 |
Reverse Pairs |
Solution |
O(nlogn) |
O(1) |
|
Hard |
Recursion |
| 494 |
Target Sum |
Solution |
O(2^n) |
O(1) |
|
Medium |
|
| 495 |
Teemo Attacking |
Solution |
O(n) |
O(1) |
|
Medium |
Array |
| 498 |
Diagonal Traverse |
Solution |
O(m*n) |
O(1) |
|
Medium |
|
| 496 |
Next Greater Element I |
Solution |
O(n*m) |
O(1) |
|
Easy |
|
| 499 |
The Maze III |
Solution |
O(m*n) |
O(m*n) |
|
Hard |
BFS |
| 500 |
Keyboard Row |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 501 |
Find Mode in Binary Tree |
Solution |
O(n) |
O(k) |
|
Easy |
Binary Tree |
| 502 |
IPO |
Solution |
O(nlogn) |
O(n) |
|
Hard |
Heap, Greedy |
| 503 |
Next Greater Element II |
Solution |
O(n) |
O(n) |
|
Medium |
Stack |
| 504 |
Base 7 |
Solution |
O(1) |
O(1) |
|
Easy |
|
| 505 |
The Maze II |
Solution |
O(m*n) |
O(m*n) |
|
Medium |
BFS |
| 506 |
Relative Ranks |
Solution |
O(nlogn) |
O(n) |
|
Easy |
|
| 507 |
Perfect Number |
Solution |
O(sqrt(n)) |
O(1) |
|
Easy |
Math |
| 508 |
Most Frequent Subtree Sum |
Solution |
O(n) |
O(n) |
|
Medium |
DFS, Tree |
| 513 |
Find Bottom Left Tree Value |
Solution |
O(n) |
O(k) |
|
Medium |
BFS |
| 514 |
Freedom Trail |
Solution |
O(?) |
O(?) |
|
Hard |
DP |
| 515 |
Find Largest Value in Each Tree Row |
Solution |
O(n) |
O(k) |
|
Medium |
BFS |
| 516 |
Longest Palindromic Subsequence |
Solution |
O(n^2) |
O(n^2) |
|
Medium |
DP |
| 517 |
Super Washing Machines |
Solution |
|
|
|
Hard |
DP |
| 520 |
Detect Capital |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 521 |
Longest Uncommon Subsequence I |
Solution |
O(max(x,y)) (x and y are length of strings) |
O(1) |
|
Easy |
|
| 522 |
Longest Uncommon Subsequence II |
Solution |
O(x*n^2) (x is average length of strings) |
O(1) |
|
Medium |
|
| 523 |
Continuous Subarray Sum |
Solution |
O(n) |
O(1) |
|
Medium |
DP |
| 524 |
Longest Word in Dictionary through Deleting |
Solution |
O(n) |
O(n) |
|
Medium |
Sort |
| 525 |
Contiguous Array |
Solution |
O(n) |
O(n) |
|
Medium |
HashMap |
| 526 |
Beautiful Arrangement |
Solution |
O(n) |
O(h) |
|
Medium |
Backtracking |
| 527 |
Word Abbreviation |
Solution |
O(n^2) |
O(n) |
|
Hard |
|
| 529 |
Minesweeper |
Solution |
O(m*n) |
O(k) |
|
Medium |
BFS |
| 530 |
Minimum Absolute Difference in BST |
Solution |
O(n) |
O(n) |
|
Easy |
DFS |
| 531 |
Lonely Pixel I |
Solution |
O(m*n) |
O(1) |
|
Medium |
|
| 532 |
K-diff Pairs in an Array |
Solution |
O(n) |
O(n) |
|
Easy |
HashMap |
| 533 |
Lonely Pixel II |
Solution |
O(m*n) |
O(m) (m is number of rows) |
|
Medium |
HashMap |
| 535 |
Encode and Decode TinyURL |
Solution |
O(1) |
O(n) |
|
Medium |
Design |
| 536 |
Construct Binary Tree from String |
Solution |
O(n) |
O(h) |
|
Medium |
Recursion, Stack |
| 537 |
Complex Number Multiplication |
Solution |
O(1) |
O(1) |
|
Medium |
Math, String |
| 538 |
Convert BST to Greater Tree |
Solution |
O(n) |
O(h) |
|
Easy |
Tree |
| 539 |
Minimum Time Difference |
Solution |
O(logn) |
O(1) |
|
Medium |
String |
| 540 |
Single Element in a Sorted Array |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 541 |
Reverse String II |
Solution |
O(n) |
O(1) |
|
Easy |
String |
| 542 |
01 Matrix |
Solution |
O(m*n) |
O(n) |
|
Medium |
BFS |
| 543 |
Diameter of Binary Tree |
Solution |
O(n) |
O(h) |
|
Easy |
Tree/DFS/Recursion |
| 544 |
Output Contest Matches |
Solution |
O(n) |
O(n) |
|
Medium |
Recursion |
| 545 |
Boundary of Binary Tree |
Solution |
O(n) |
O(n) |
|
Medium |
Recursion |
| 546 |
Remove Boxes |
Solution |
O(n^3) |
O(n^3) |
|
Hard |
DFS, DP |
| 547 |
Friend Circles |
Solution |
O(n^2) |
O(n) |
|
Medium |
Union Find |
| 548 |
Split Array with Equal Sum |
Solution |
O(n^2) |
O(n) |
|
Medium |
Array |
| 549 |
Binary Tree Longest Consecutive Sequence II |
Solution |
O(n) |
O(n) |
|
Medium |
Tree |
| 551 |
Student Attendance Record I |
Solution |
O(n) |
O(1) |
|
Easy |
String |
| 552 |
Student Attendance Record II |
Solution |
O(n) |
O(1) |
|
Hard |
DP |
| 553 |
Optimal Division |
Solution |
O(n) |
O(n) |
|
Medium |
String, Math |
| 554 |
Brick Wall |
Solution |
O(n) (n is total number of bricks in the wall) |
O(m) (m is width of the wall) |
|
Medium |
HashMap |
| 555 |
Split Concatenated Strings |
Solution |
O(n^2) |
O(n) |
|
Medium |
String |
| 556 |
Next Greater Element III |
Solution |
O(n) |
O(1) |
|
Medium |
String |
| 557 |
Reverse Words in a String III |
Solution |
O(n) |
O(n) |
|
Easy |
String |
| 560 |
Subarray Sum Equals K |
Solution |
O(n) |
O(n) |
|
Medium |
Array, HashMap |
| 561 |
Array Partition I |
Solution |
O(nlogn) |
O(1) |
|
Easy |
Array |
| 562 |
Longest Line of Consecutive One in Matrix |
Solution |
O(m*n) |
O(m*n) |
|
Medium |
Matrix DP |
| 563 |
Binary Tree Tilt |
Solution |
O(n) |
O(n) |
|
Easy |
Tree Recursion |
| 565 |
Array Nesting |
Solution |
O(n) |
O(n) |
|
Medium |
|
| 566 |
Reshape the Matrix |
Solution |
O(m*n) |
O(1) |
|
Easy |
|
| 567 |
Permutation in String |
Solution |
O(l1 + 26*(l2 - l1)) |
O(1) |
|
Medium |
Sliding Windows, Two Pointers |
| 568 |
Maximum Vacation Days |
Solution |
O(n^2*k) |
O(n*k) |
|
Hard |
DP |
| 572 |
Subtree of Another Tree |
Solution |
O(m*n) |
O(1) |
|
Easy |
Tree |
| 573 |
Squirrel Simulation |
Solution |
O(n) |
O(1) |
|
Medium |
Math |
| 575 |
Distribute Candies |
Solution |
O(nlogn) |
O(1) |
|
Easy |
Array |
| 576 |
Out of Boundary Paths |
Solution |
O(Nmn) |
O(m*n) |
|
Hard |
DP, DFS |
| 581 |
Shortest Unsorted Continuous Subarray |
Solution |
O(n) |
O(1) |
|
Easy |
Array, Sort |
| 582 |
Kill Process |
Solution |
O(n) |
O(h) |
|
Medium |
Stack |
| 583 |
Delete Operation for Two Strings |
Solution |
O(m*n) |
O(m*n) could be optimized to O(n) |
|
Medium |
DP |
| 587 |
Erect the Fence |
Solution |
O(?) |
O(?) |
|
Hard |
Geometry |
| 588 |
Design In-Memory File System |
Solution |
O(n) |
O(h) |
|
Hard |
Trie, Design |
| 591 |
Tag Validator |
Solution |
O(n) |
O(n) |
|
Hard |
Stack, String |
| 592 |
Fraction Addition and Subtraction |
Solution |
O(nlogx) |
O(n) |
|
Medium |
Math |
| 593 |
Valid Square |
Solution |
O(1) |
O(1) |
|
Medium |
Math |
| 594 |
Longest Harmonious Subsequence |
Solution |
O(n) |
O(n) |
|
Easy |
Array, HashMap |
| 598 |
Range Addition II |
Solution |
O(x) (x is the number of operations) |
O(1) |
|
Easy |
|
| 599 |
Minimum Index Sum of Two Lists |
Solution |
O(max(m,n)) |
O(max(m,n)) |
|
Easy |
HashMap |
| 600 |
Non-negative Integers without Consecutive Ones |
Solution |
O(log2(max_int) = 32) |
O(log2(max_int) = 32) |
|
Hard |
Bit Manipulation, DP |
| 604 |
Design Compressed String Iterator |
Solution |
O(n) |
O(n) |
|
Easy |
Design, String |
| 605 |
Can Place Flowers |
Solution |
O(n) |
O(1) |
|
Easy |
Array |
| 606 |
Construct String from Binary Tree |
Solution |
O(n) |
O(n) |
|
Easy |
Tree, Recursion |
| 609 |
Find Duplicate File in System |
Solution |
O(n*x) (x is the average length of each string) |
O(n*x) |
|
Medium |
HashMap |
| 611 |
Valid Triangle Number |
Solution |
O(n^2logn) |
O(logn) |
|
Medium |
Binary Search |
| 616 |
Add Bold Tag in String |
Solution |
O(n*k) (n is length of string, k is size of dict) |
O(n) |
|
Medium |
String |
| 617 |
Merge Two Binary Trees |
Solution |
O(n) |
O(h) |
|
Easy |
Tree, Recursion |
| 621 |
Task Scheduler |
Solution |
O(n) |
O(26) |
|
Medium |
Greedy, Queue |
| 623 |
Add One Row to Tree |
Solution |
O(n) |
O(h) |
|
Medium |
Tree |
| 624 |
Maximum Distance in Arrays |
Solution |
O(nlogn) |
O(1) |
|
Easy |
Sort, Array |
| 625 |
Minimum Factorization |
Solution |
O(?) |
O(?) |
|
Medium |
|
| 628 |
Maximum Product of Three Numbers |
Solution |
O(nlogn) |
O(1) |
|
Easy |
|
| 629 |
K Inverse Pairs Array |
Solution |
O(n*k) |
O(n*k) |
|
Hard |
DP |
| 630 |
Course Schedule III |
Solution |
O(n*logn) |
O(n) |
|
Hard |
Heap, Greedy |
| 631 |
Design Excel Sum Formula |
Solution |
|
|
|
Hard |
Design, Topological Sort |
| 632 |
Smallest Range |
Solution |
O(n*logk) |
O(k) |
|
Hard |
Heap |
| 633 |
Sum of Square Numbers |
Solution |
O(logn) |
O(1) |
|
Easy |
Binary Search |
| 634 |
Find the Derangement of An Array |
Solution |
O(n) |
O(1) |
|
Medium |
Math |
| 635 |
Design Log Storage System |
Solution |
O(n) |
O(n) |
|
Medium |
Design |
| 636 |
Exclusive Time of Functions |
Solution |
O(n) |
O(n/2) |
|
Medium |
Stack |
| 637 |
Average of Levels in Binary Tree |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 638 |
Shopping Offers |
Solution |
O(2^n) |
O(n) |
|
Medium |
DP, DFS |
| 639 |
Decode Ways II |
Solution |
O(n) |
O(n) |
|
Hard |
DP |
| 640 |
Solve the Equation |
Solution |
O(n) |
O(n) |
|
Medium |
|
| 642 |
Design Search Autocomplete System |
Solution |
O(n) |
O(n) |
|
Hard |
Design |
| 643 |
Maximum Average Subarray I |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 644 |
Maximum Average Subarray II |
Solution |
|
O(1) |
|
Hard |
Binary Search |
| 645 |
Set Mismatch |
Solution |
O(nlogn) |
O(1) |
|
Easy |
|
| 646 |
Maximum Length of Pair Chain |
Solution |
O(nlogn) |
O(1) |
|
Medium |
DP, Greedy |
| 647 |
Palindromic Substrings |
Solution |
O(n^2) |
O(1) |
|
Medium |
DP |
| 648 |
Replace Words |
Solution |
O(n) |
O(n) |
|
Medium |
Trie |
| 649 |
Dota2 Senate |
Solution |
O(n) |
O(n) |
|
Medium |
Greedy |
| 650 |
2 Keys Keyboard |
Solution |
O(n^2) |
O(n) |
|
Medium |
DP |
| 651 |
4 Keys Keyboard |
Solution |
O(n^2) |
O(n) |
|
Medium |
DP |
| 652 |
Find Duplicate Subtrees |
Solution |
O(n) |
O(n) |
|
Medium |
Tree |
| 653 |
Two Sum IV - Input is a BST |
Solution |
|
|
|
Easy |
Tree |
| 654 |
Maximum Binary Tree |
Solution |
O(n) |
O(n) |
|
Medium |
Tree |
| 655 |
Print Binary Tree |
Solution |
O(h*2^h) |
O(h*2^h) |
|
Medium |
Recursion |
| 656 |
Coin Path |
Solution |
O(n*B) |
O(n) |
|
Hard |
DP |
| 657 |
Judge Route Circle |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 658 |
Find K Closest Elements |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 659 |
Split Array into Consecutive Subsequences |
Solution |
O(n) |
O(n) |
|
Medium |
HashMap |
| 660 |
Remove 9 |
Solution |
O(n) |
O(1) |
|
Hard |
Math |
| 661 |
Image Smoother |
Solution |
O(m*n) |
O(1) |
|
Easy |
Array |
| 662 |
Maximum Width of Binary Tree |
Solution |
O(n) |
O(k) |
|
Medium |
BFS, DFS |
| 663 |
Equal Tree Partition |
Solution |
O(n) |
O(n) |
|
Medium |
Tree |
| 664 |
Strange Printer |
Solution |
O(n^3) |
O(n^2) |
|
Hard |
DP |
| 665 |
Non-decreasing Array |
Solution |
O(n) |
O(n) |
|
Easy |
|
| 666 |
Path Sum IV |
Solution |
O(1) |
O(1) |
|
Medium |
Tree, DFS |
| 667 |
Beautiful Arrangement II |
Solution |
O(n) |
O(1) |
|
Medium |
Array |
| 668 |
Kth Smallest Number in Multiplication Table |
Solution |
O(logm*n) |
O(1) |
|
Hard |
Binary Search |
| 669 |
Trim a Binary Search Tree |
Solution |
O(n) |
O(1) |
|
Easy |
Tree, DFS |
| 670 |
Maximum Swap |
Solution |
O(n^2) |
O(1) |
|
Medium |
String |
| 671 |
Second Minimum Node In a Binary Tree |
Solution |
O(n) |
O(n) |
|
Easy |
Tree, DFS |
| 672 |
Bulb Switcher II |
Solution |
O(1) |
O(1) |
|
Medium |
Math |
| 673 |
Number of Longest Increasing Subsequence |
Solution |
O(n^2) |
O(n) |
|
Medium |
DP |
| 674 |
Longest Continuous Increasing Subsequence |
Solution |
O(n^2) |
O(1) |
|
Easy |
|
| 675 |
Cut Off Trees for Golf Event |
Solution |
O((m*n)^2) |
O(m*n) |
|
Hard |
BFS |
| 676 |
Implement Magic Dictionary |
Solution |
O(n^2) |
O(n) |
|
Medium |
|
| 677 |
Map Sum Pairs |
Solution |
O(n) |
O(n) |
|
Medium |
HashMap |
| 678 |
Valid Parenthesis String |
Solution |
O(n) |
O(1) |
|
Medium |
Recursion, Greedy |
| 679 |
24 Game |
Solution |
O(1) (Upper bound 9216) |
O(1) |
|
Hard |
Recursion |
| 680 |
Valid Palindrome II |
Solution |
O(n) |
O(1) |
|
Easy |
String |
| 681 |
Next Closest Time |
Solution |
O(1) |
O(1) |
|
Medium |
|
| 682 |
Baseball Game |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 683 |
K Empty Slots |
Solution |
O(n) |
O(n) |
|
Hard |
|
| 684 |
Redundant Connection |
Solution |
O(n) |
O(n) |
|
Medium |
Union Find |
| 685 |
Redundant Connection II |
Solution |
O(n) |
O(n) |
|
Hard |
Union Find |
| 686 |
Repeated String Match |
Solution |
O(n*(m+n)) |
O(m+n) |
|
Easy |
|
| 687 |
Longest Univalue Path |
Solution |
O(n) |
O(h) |
|
Easy |
DFS |
| 688 |
Knight Probability in Chessboard |
Solution |
O(n^2) |
O(n^2) |
|
Medium |
DP |
| 689 |
Maximum Sum of 3 Non-Overlapping Subarrays |
Solution |
O(n) |
O(n) |
|
Hard |
DP |
| 690 |
Employee Importance |
Solution |
O(n) |
O(h) |
|
Easy |
DFS |
| 691 |
Stickers to Spell Word |
Solution |
O(?) |
O(?) |
|
Hard |
DP |
| 692 |
Top K Frequent Words |
Solution |
O(nlogk) |
O(n) |
|
Medium |
|
| 693 |
Binary Number with Alternating Bits |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 694 |
Number of Distinct Islands |
Solution |
O(m*n) |
O(1) |
|
Medium |
DFS |
| 695 |
Max Area of Island |
Solution |
O(m*n) |
O(1) |
|
Easy |
DFS |
| 696 |
Count Binary Substrings |
Solution |
O(n) |
O(n) |
|
Easy |
|
| 697 |
Degree of an Array |
Solution |
O(n) |
O(n) |
|
Easy |
|
| 698 |
Partition to K Equal Sum Subsets |
Solution |
O(n*(2^n)) |
O(2^n) |
|
Medium |
Backtracking |
| 699 |
Falling Squares |
Solution |
O(n^2) |
O(n) |
|
Hard |
Segment Tree |
| 712 |
Minimum ASCII Delete Sum for Two Strings |
Solution |
O(m*n) |
O(m*n) |
|
Medium |
DP |
| 713 |
Subarray Product Less Than K |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 714 |
Best Time to Buy and Sell Stock with Transaction Fee |
Solution |
O(n) |
O(1) |
|
Medium |
DP |
| 716 |
Max Stack |
Solution |
O(logn) |
O(n) |
|
Hard |
Design |
| 717 |
1-bit and 2-bit Characters |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 718 |
Maximum Length of Repeated Subarray |
Solution |
O(m*n) |
O(m*n) |
|
Medium |
DP |
| 719 |
Find K-th Smallest Pair Distance |
Solution |
O(nlogw + nlogn) |
O(1) |
|
Hard |
Binary Search |
| 720 |
Longest Word in Dictionary |
Solution |
O(��wi) where wi is the length of words[i] |
O(��wi) where wi is the length of words[i] |
|
Easy |
Trie |
| 721 |
Accounts Merge |
Solution |
|
|
|
Medium |
DFS, Union Find |
| 723 |
Candy Crush |
Solution |
O((r*c)^2) |
O((r*c)) |
|
Medium |
Array, Two Pointers |
| 724 |
Find Pivot Index |
Solution |
O(n) |
O(1) |
|
Easy |
Array |
| 725 |
Split Linked List in Parts |
Solution |
O(n+k) |
O(k) |
|
Medium |
LinkedList |
| 727 |
Minimum Window Subsequence |
Solution |
O(m*n) |
O(m*n) |
|
Hard |
DP |
| 728 |
Self Dividing Numbers |
Solution |
O(n*k) k is the average number of digits of each number in the given array |
O(1) |
|
Easy |
|
| 729 |
My Calendar I |
Solution |
O(n) |
O(n) |
|
Medium |
|
| 733 |
Flood Fill |
Solution |
O(m*n) |
O(m*n) |
|
Easy |
BFS, DFS |
| 734 |
Sentence Similarity |
Solution |
O(n*k) |
O(1) |
|
Easy |
HashTable |
| 735 |
Asteroid Collision |
Solution |
O(n) |
O(n) |
|
Medium |
Stack |
| 737 |
Sentence Similarity II |
Solution |
O(nlogk + k) n is the length of max(words1, words2), k is the length of pairs |
O(k) |
|
Medium |
Union Find |
| 738 |
Monotone Increasing Digits |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 739 |
Daily Temperatures |
Solution |
O(n^2) |
O(1) |
|
Medium |
|
| 740 |
Delete and Earn |
Solution |
O(n) |
O(n) |
|
Medium |
|
| 744 |
Find Smallest Letter Greater Than Target |
Solution |
O(logn) |
O(1) |
|
Easy |
|
| 746 |
Min Cost Climbing Stairs |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 747 |
Largest Number Greater Than Twice of Others |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 748 |
Shortest Completing Word |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 750 |
Number Of Corner Rectangles |
Solution |
O((m*n)^2) |
O(1) |
|
Medium |
|
| 754 |
Reach a Number |
Solution |
O(n) |
O(1) |
|
Medium |
Math |
| 755 |
Pour Water |
Solution |
O(V*N) |
O(1) |
|
Medium |
Array |
| 756 |
Pyramid Transition Matrix |
Solution |
O(?) |
O(?) |
|
Medium |
Backtracking |
| 758 |
Bold Words in String |
Solution |
O(n*k) |
O(n |
|
Easy |
|
| 760 |
Find Anagram Mappings |
Solution |
O(n^2) |
O(1) |
|
Easy |
|
| 762 |
Prime Number of Set Bits in Binary Representation |
Solution |
O(n) |
O(1) |
|
Easy |
|
| 763 |
Partition Labels |
Solution |
O(n) |
O(1) |
|
Medium |
|
| 764 |
Largest Plus Sign |
Solution |
O(n^2) |
O(n^2) |
|
Medium |
DP |
| 765 |
Couples Holding Hands |
Solution |
O(n^2) |
O(1) |
|
Hard |
|
