1 |
Two Sum |
Easy |
2 |
Add Two Numbers |
Medium |
3 |
Longest Substring Without Repeating Characters |
Medium |
4 |
Median of Two Sorted Arrays |
Hard |
5 |
Longest Palindromic Substring |
Medium |
6 |
ZigZag Conversion |
Medium |
7 |
Reverse Integer |
Easy |
8 |
String to Integer (atoi) |
Medium |
9 |
Palindrome Number |
Easy |
10 |
Regular Expression Matching |
Hard |
11 |
Container With Most Water |
Medium |
12 |
Integer to Roman |
Medium |
13 |
Roman to Integer |
Easy |
14 |
Longest Common Prefix |
Easy |
15 |
3Sum |
Medium |
16 |
3Sum Closest |
Medium |
17 |
Letter Combinations of a Phone Number |
Medium |
18 |
4Sum |
Medium |
19 |
Remove Nth Node From End of List |
Medium |
20 |
Valid Parentheses |
Easy |
21 |
Merge Two Sorted Lists |
Easy |
22 |
Generate Parentheses |
Medium |
23 |
Merge k Sorted Lists |
Hard |
24 |
Swap Nodes in Pairs |
Medium |
25 |
Reverse Nodes in k-Group |
Hard |
26 |
Remove Duplicates from Sorted Array |
Easy |
27 |
Remove Element |
Easy |
28 |
Implement strStr() |
Easy |
29 |
Divide Two Integers |
Medium |
30 |
Substring with Concatenation of All Words |
Hard |
31 |
Next Permutation |
Medium |
32 |
Longest Valid Parentheses |
Hard |
33 |
Search in Rotated Sorted Array |
Medium |
34 |
Find First and Last Position of Element in Sorted Array |
Medium |
35 |
Search Insert Position |
Easy |
36 |
Valid Sudoku |
Medium |
37 |
Sudoku Solver |
Hard |
38 |
Count and Say |
Medium |
39 |
Combination Sum |
Medium |
40 |
Combination Sum II |
Medium |
41 |
First Missing Positive |
Hard |
42 |
Trapping Rain Water |
Hard |
43 |
Multiply Strings |
Medium |
44 |
Wildcard Matching |
Hard |
45 |
Jump Game II |
Medium |
46 |
Permutations |
Medium |
47 |
Permutations II |
Medium |
48 |
Rotate Image |
Medium |
49 |
Group Anagrams |
Medium |
50 |
Pow(x, n) |
Medium |
51 |
N-Queens |
Hard |
52 |
N-Queens II |
Hard |
53 |
Maximum Subarray |
Easy |
54 |
Spiral Matrix |
Medium |
55 |
Jump Game |
Medium |
56 |
Merge Intervals |
Medium |
57 |
Insert Interval |
Medium |
58 |
Length of Last Word |
Easy |
59 |
Spiral Matrix II |
Medium |
62 |
Unique Paths |
Medium |
64 |
Minimum Path Sum |
Medium |
66 |
Plus One |
Easy |
67 |
Add Binary |
Easy |
69 |
Sqrt(x) |
Medium |
70 |
Climbing Stairs |
Easy |
73 |
Set Matrix Zeroes |
Medium |
74 |
Search a 2D Matrix |
Medium |
77 |
Combinations |
Medium |
78 |
Subsets |
Medium |
80 |
Remove Duplicates from Sorted Array II |
Medium |
83 |
Remove Duplicates from Sorted List |
Easy |
86 |
Partition List |
Medium |
88 |
Merge Sorted Array |
Easy |
90 |
Subsets II |
Medium |
93 |
Restore IP Addresses |
Medium |
94 |
Binary Tree Inorder Traversal |
Easy |
95 |
Unique Binary Search Trees II |
Medium |
96 |
Unique Binary Search Trees |
Medium |
98 |
Validate Binary Search Tree |
Medium |
100 |
Same Tree |
Easy |
101 |
Symmetric Tree |
Easy |
102 |
Binary Tree Level Order Traversal |
Medium |
104 |
Maximum Depth of Binary Tree |
Easy |
111 |
Minimum Depth of Binary Tree |
Easy |
112 |
Path Sum |
Easy |
116 |
Populating Next Right Pointers in Each Node |
Medium |
118 |
Pascal's Triangle |
Easy |
119 |
Pascal's Triangle II |
Easy |
120 |
Triangle |
Medium |
121 |
Best Time to Buy and Sell Stock |
Easy |
125 |
Valid Palindrome |
Easy |
128 |
Longest Consecutive Sequence |
Medium |
131 |
Palindrome Partitioning |
Medium |
133 |
Clone Graph |
Medium |
134 |
Gas Station |
Medium |
135 |
Candy |
Hard |
136 |
Single Number |
Easy |
137 |
Single Number II |
Medium |
138 |
Copy List with Random Pointer |
Medium |
139 |
Word Break |
Medium |
140 |
Word Break II |
Hard |
141 |
Linked List Cycle |
Easy |
142 |
Linked List Cycle II |
Medium |
143 |
Reorder List |
Medium |
144 |
Binary Tree Preorder Traversal |
Easy |
145 |
Binary Tree Postorder Traversal |
Easy |
149 |
Max Points on a Line |
Hard |
151 |
Reverse Words in a String |
Medium |
152 |
Maximum Product Subarray |
Medium |
160 |
Intersection of Two Linked Lists |
Medium |
167 |
Two Sum II - Input Array Is Sorted |
Easy |
169 |
Majority Element |
Easy |
179 |
Largest Number |
Medium |
189 |
Rotate Array |
Medium |
190 |
Reverse Bits |
Easy |
191 |
Number of 1 Bits |
Easy |
198 |
House Robber |
Medium |
202 |
Happy Number |
Easy |
203 |
Remove Linked List Elements |
Easy |
204 |
Count Primes |
Medium |
206 |
Reverse Linked List |
Easy |
207 |
Course Schedule |
Medium |
213 |
House Robber II |
Medium |
214 |
Shortest Palindrome |
Hard |
215 |
Kth Largest Element in an Array |
Medium |
217 |
Contains Duplicate |
Easy |
219 |
Contains Duplicate II |
Easy |
225 |
Implement Stack using Queues |
Easy |
226 |
Invert Binary Tree |
Easy |
229 |
Majority Element II |
Medium |
231 |
Power of Two |
Easy |
232 |
Implement Queue using Stacks |
Easy |
234 |
Palindrome Linked List |
Easy |
235 |
Lowest Common Ancestor of a Binary Search Tree |
Easy |
237 |
Delete Node in a Linked List |
Easy |
242 |
Valid Anagram |
Easy |
263 |
Ugly Number |
Easy |
264 |
Ugly Number II |
Medium |
268 |
Missing Number |
Easy |
273 |
Integer to English Words |
Hard |
278 |
First Bad Version |
Medium |
283 |
Move Zeroes |
Easy |
290 |
Word Pattern |
Easy |
316 |
Remove Duplicate Letters |
Medium |
326 |
Power of Three |
Easy |
342 |
Power of Four |
Easy |
344 |
Reverse String |
Easy |
345 |
Reverse Vowels of a String |
Easy |
347 |
Top K Frequent Elements |
Medium |
349 |
Intersection of Two Arrays |
Easy |
350 |
Intersection of Two Arrays II |
Easy |
367 |
Valid Perfect Square |
Easy |
371 |
Sum of Two Integers |
Medium |
372 |
Super Pow |
Medium |
374 |
Guess Number Higher or Lower |
Medium |
383 |
Ransom Note |
Easy |
387 |
First Unique Character in a String |
Easy |
405 |
Convert a Number to Hexadecimal |
Easy |
414 |
Third Maximum Number |
Easy |
419 |
Battleships in a Board |
Medium |
442 |
Find All Duplicates in an Array |
Medium |
448 |
Find All Numbers Disappeared in an Array |
Easy |
451 |
Sort Characters By Frequency |
Medium |
452 |
Minimum Number of Arrows to Burst Balloons |
Medium |
459 |
Repeated Substring Pattern |
Easy |
461 |
Hamming Distance |
Easy |
463 |
Island Perimeter |
Medium |
476 |
Number Complement |
Easy |
491 |
Non-decreasing Subsequences |
Medium |
492 |
Construct the Rectangle |
Easy |
500 |
Keyboard Row |
Easy |
501 |
Find Mode in Binary Search Tree |
Easy |
502 |
IPO |
Hard |
503 |
Next Greater Element II |
Medium |
504 |
Base 7 |
Easy |
506 |
Relative Ranks |
Easy |
509 |
Fibonacci Number |
Easy |
520 |
Detect Capital |
Easy |
541 |
Reverse String II |
Easy |
542 |
01 Matrix |
Medium |
551 |
Student Attendance Record I |
Easy |
557 |
Reverse Words in a String III |
Easy |
563 |
Binary Tree Tilt |
Easy |
565 |
Array Nesting |
Medium |
566 |
Reshape the Matrix |
Easy |
567 |
Permutation in String |
Medium |
599 |
Minimum Index Sum of Two Lists |
Easy |
606 |
Construct String from Binary Tree |
Easy |
617 |
Merge Two Binary Trees |
Easy |
628 |
Maximum Product of Three Numbers |
Easy |
645 |
Set Mismatch |
Medium |
648 |
Replace Words |
Medium |
653 |
Two Sum IV - Input is a BST |
Easy |
680 |
Valid Palindrome II |
Easy |
686 |
Repeated String Match |
Easy |
695 |
Max Area of Island |
Medium |
700 |
Search in a Binary Search Tree |
Easy |
701 |
Insert into a Binary Search Tree |
Medium |
704 |
Binary Search |
Easy |
705 |
Design HashSet |
Easy |
706 |
Design HashMap |
Easy |
713 |
Subarray Product Less Than K |
Medium |
722 |
Remove Comments |
Medium |
733 |
Flood Fill |
Easy |
739 |
Daily Temperatures |
Medium |
746 |
Min Cost Climbing Stairs |
Easy |
747 |
Largest Number At Least Twice of Others |
Easy |
762 |
Prime Number of Set Bits in Binary Representation |
Easy |
784 |
Letter Case Permutation |
Medium |
791 |
Custom Sort String |
Medium |
796 |
Rotate String |
Easy |
804 |
Unique Morse Code Words |
Easy |
819 |
Most Common Word |
Easy |
821 |
Shortest Distance to a Character |
Easy |
824 |
Goat Latin |
Easy |
831 |
Masking Personal Information |
Medium |
844 |
Backspace String Compare |
Easy |
846 |
Hand of Straights |
Medium |
867 |
Transpose Matrix |
Easy |
876 |
Middle of the Linked List |
Easy |
884 |
Uncommon Words from Two Sentences |
Easy |
890 |
Find and Replace Pattern |
Medium |
905 |
Sort Array By Parity |
Easy |
916 |
Word Subsets |
Medium |
922 |
Sort Array By Parity II |
Easy |
925 |
Long Pressed Name |
Easy |
926 |
Flip String to Monotone Increasing |
Medium |
929 |
Unique Email Addresses |
Easy |
966 |
Vowel Spellchecker |
Medium |
970 |
Powerful Integers |
Easy |
976 |
Largest Perimeter Triangle |
Easy |
977 |
Squares of a Sorted Array |
Easy |
985 |
Sum of Even Numbers After Queries |
Easy |
989 |
Add to Array-Form of Integer |
Easy |
994 |
Rotting Oranges |
Medium |
997 |
Find the Town Judge |
Easy |
1002 |
Find Common Characters |
Easy |
1009 |
Complement of Base 10 Integer |
Easy |
1010 |
Pairs of Songs With Total Durations Divisible by 60 |
Medium |
1022 |
Sum of Root To Leaf Binary Numbers |
Easy |
1037 |
Valid Boomerang |
Easy |
1041 |
Robot Bounded In Circle |
Medium |
1081 |
Smallest Subsequence of Distinct Characters |
Medium |
1103 |
Distribute Candies to People |
Easy |
1108 |
Defanging an IP Address |
Easy |
1189 |
Maximum Number of Balloons |
Easy |
1207 |
Unique Number of Occurrences |
Easy |
1232 |
Check If It Is a Straight Line |
Easy |
1233 |
Remove Sub-Folders from the Filesystem |
Medium |
1249 |
Minimum Remove to Make Valid Parentheses |
Medium |
1252 |
Cells with Odd Values in a Matrix |
Easy |
1287 |
Element Appearing More Than 25% In Sorted Array |
Easy |
1290 |
Convert Binary Number in a Linked List to Integer |
Easy |
1291 |
Sequential Digits |
Medium |
1292 |
Maximum Side Length of a Square with Sum Less than or Equal to Threshold |
Medium |
1295 |
Find Numbers with Even Number of Digits |
Easy |
1296 |
Divide Array in Sets of K Consecutive Numbers |
Medium |
1297 |
Maximum Number of Occurrences of a Substring |
Medium |
1304 |
Find N Unique Integers Sum up to Zero |
Easy |
1309 |
Decrypt String from Alphabet to Integer Mapping |
Easy |
1313 |
Decompress Run-Length Encoded List |
Easy |
1317 |
Convert Integer to the Sum of Two No-Zero Integers |
Easy |
1318 |
Minimum Flips to Make a OR b Equal to c |
Medium |
1323 |
Maximum 69 Number |
Easy |
1324 |
Print Words Vertically |
Medium |
1331 |
Rank Transform of an Array |
Easy |
1332 |
Remove Palindromic Subsequences |
Easy |
1333 |
Filter Restaurants by Vegan-Friendly, Price and Distance |
Medium |
1342 |
Number of Steps to Reduce a Number to Zero |
Easy |
1351 |
Count Negative Numbers in a Sorted Matrix |
Easy |
1356 |
Sort Integers by The Number of 1 Bits |
Easy |
1360 |
Number of Days Between Two Dates |
Easy |
1365 |
How Many Numbers Are Smaller Than the Current Number |
Easy |
1374 |
Generate a String With Characters That Have Odd Counts |
Easy |
1380 |
Lucky Numbers in a Matrix |
Easy |
1389 |
Create Target Array in the Given Order |
Easy |
1402 |
Reducing Dishes |
Hard |
1408 |
String Matching in an Array |
Easy |
1410 |
HTML Entity Parser |
Medium |
1431 |
Kids With the Greatest Number of Candies |
Easy |
1436 |
Destination City |
Easy |
1437 |
Check If All 1's Are at Least Length K Places Away |
Easy |
1443 |
Minimum Time to Collect All Apples in a Tree |
Medium |
1446 |
Consecutive Characters |
Easy |
1447 |
Simplified Fractions |
Medium |
1450 |
Number of Students Doing Homework at a Given Time |
Easy |
1451 |
Rearrange Words in a Sentence |
Medium |
1455 |
Check If a Word Occurs As a Prefix of Any Word in a Sentence |
Easy |
1456 |
Maximum Number of Vowels in a Substring of Given Length |
Medium |
1460 |
Make Two Arrays Equal by Reversing Sub-arrays |
Easy |
1464 |
Maximum Product of Two Elements in an Array |
Easy |
1470 |
Shuffle the Array |
Easy |
1472 |
Design Browser History |
Medium |
1475 |
Final Prices With a Special Discount in a Shop |
Easy |
1480 |
Running Sum of 1d Array |
Easy |
1481 |
Least Number of Unique Integers after K Removals |
Medium |
1486 |
XOR Operation in an Array |
Easy |
1491 |
Average Salary Excluding the Minimum and Maximum Salary |
Easy |
1492 |
The kth Factor of n |
Medium |
1493 |
Longest Subarray of 1's After Deleting One Element |
Medium |
1496 |
Path Crossing |
Easy |
1502 |
Can Make Arithmetic Progression From Sequence |
Easy |
1507 |
Reformat Date |
Easy |
1512 |
Number of Good Pairs |
Easy |
1519 |
Number of Nodes in the Sub-Tree With the Same Label |
Medium |
1528 |
Shuffle String |
Easy |
1550 |
Three Consecutive Odds |
Easy |
1551 |
Minimum Operations to Make Array Equal |
Medium |
1566 |
Detect Pattern of Length M Repeated K or More Times |
Easy |
1576 |
Replace All ?'s to Avoid Consecutive Repeating Characters |
Medium |
1598 |
Crawler Log Folder |
Easy |
1668 |
Maximum Repeating Substring |
Easy |
1669 |
Merge In Between Linked Lists |
Medium |
1672 |
Richest Customer Wealth |
Easy |
1716 |
Calculate Money in Leetcode Bank |
Easy |
1748 |
Sum of Unique Elements |
Easy |
1780 |
Check if Number is a Sum of Powers of Three |
Medium |
1791 |
Find Center of Star Graph |
Easy |
1812 |
Determine Color of a Chessboard Square |
Easy |
1817 |
Finding the Users Active Minutes |
Medium |
1832 |
Check if the Sentence Is Pangram |
Easy |
1880 |
Check if Word Equals Summation of Two Words |
Easy |
1886 |
Determine Whether Matrix Can Be Obtained By Rotation |
Easy |
1920 |
Build Array from Permutation |
Easy |
1929 |
Concatenation of Array |
Easy |
1935 |
Maximum Number of Words You Can Type |
Easy |
1996 |
The Number of Weak Characters in the Game |
Medium |
2000 |
Reverse Prefix of Word |
Easy |
2011 |
Final Value of Variable After Performing Operations |
Easy |
2016 |
Maximum Difference Between Increasing Elements |
Easy |
2027 |
Minimum Moves to Convert String |
Easy |
2047 |
Number of Valid Words in a Sentence |
Easy |
2053 |
Kth Distinct String in an Array |
Medium |
2085 |
Count Common Words With One Occurrence |
Easy |
2095 |
Delete the Middle Node of a Linked List |
Medium |
2099 |
Find Subsequence of Length K With the Largest Sum |
Medium |
2114 |
Maximum Number of Words Found in Sentences |
Easy |
2129 |
Capitalize the Title |
Easy |
2154 |
Keep Multiplying Found Values by Two |
Easy |
2235 |
Add Two Integers |
Easy |
2244 |
Minimum Rounds to Complete All Tasks |
Medium |
2396 |
Strictly Palindromic Number |
Medium |
2413 |
Smallest Even Multiple |
Easy |
2427 |
Number of Common Factors |
Easy |
2469 |
Convert the Temperature |
Easy |
2482 |
Difference Between Ones and Zeros in Row and Column |
Medium |
2490 |
Circular Sentence |
Easy |
2529 |
Maximum Count of Positive Integer and Negative Integer |
Easy |
2535 |
Difference Between Element Sum and Digit Sum of an Array |
Easy |