| 0001 |
Two Sum |
Easy |
| 0009 |
Palindrome Number |
Easy |
| 0013 |
Roman to Integer |
Easy |
| 0014 |
Longest Common Prefix |
Easy |
| 0020 |
Valid Parentheses |
Easy |
| 0021 |
Merge Two Sorted Lists |
Easy |
| 0026 |
Remove Duplicates from Sorted Array |
Easy |
| 0027 |
Remove Element |
Easy |
| 0028 |
Find the Index of the First Occurrence in a String |
Easy |
| 0035 |
Search Insert Position |
Easy |
| 0058 |
Length of Last Word |
Easy |
| 0066 |
Plus One |
Easy |
| 0067 |
Add Binary |
Easy |
| 0069 |
Sqrt(x) |
Easy |
| 0070 |
Climbing Stairs |
Easy |
| 0083 |
Remove Duplicates from Sorted List |
Easy |
| 0088 |
Merge Sorted Array |
Easy |
| 0094 |
Binary Tree Inorder Traversal |
Easy |
| 0100 |
Same Tree |
Easy |
| 0101 |
Symmetric Tree |
Easy |
| 0104 |
Maximum Depth of Binary Tree |
Easy |
| 0108 |
Convert Sorted Array to Binary Search Tree |
Easy |
| 0110 |
Balanced Binary Tree |
Easy |
| 0111 |
Minimum Depth of Binary Tree |
Easy |
| 0112 |
Path Sum |
Easy |
| 0118 |
Pascal’s Triangle |
Easy |
| 0119 |
Pascal’s Triangle II |
Easy |
| 0121 |
Best Time to Buy and Sell Stock |
Easy |
| 0125 |
Valid Palindrome |
Easy |
| 0136 |
Single Number |
Easy |
| 0141 |
Linked List Cycle |
Easy |
| 0144 |
Binary Tree Preorder Traversal |
Easy |
| 0145 |
Binary Tree Postorder Traversal |
Easy |
| 0157 |
Read N Characters Given Read4 |
Easy |
| 0160 |
Intersection of Two Linked Lists |
Easy |
| 0163 |
Missing Ranges |
Easy |
| 0168 |
Excel Sheet Column Title |
Easy |
| 0169 |
Majority Element |
Easy |
| 0170 |
Two Sum III - Data structure design |
Easy |
| 0171 |
Excel Sheet Column Number |
Easy |
| 0175 |
Combine Two Tables |
Easy |
| 0181 |
Employees Earning More Than Their Managers |
Easy |
| 0182 |
Duplicate Emails |
Easy |
| 0183 |
Customers Who Never Order |
Easy |
| 0190 |
Reverse Bits |
Easy |
| 0191 |
Number of 1 Bits |
Easy |
| 0193 |
Valid Phone Numbers |
Easy |
| 0195 |
Tenth Line |
Easy |
| 0196 |
Delete Duplicate Emails |
Easy |
| 0197 |
Rising Temperature |
Easy |
| 0202 |
Happy Number |
Easy |
| 0203 |
Remove Linked List Elements |
Easy |
| 0205 |
Isomorphic Strings |
Easy |
| 0206 |
Reverse Linked List |
Easy |
| 0217 |
Contains Duplicate |
Easy |
| 0219 |
Contains Duplicate II |
Easy |
| 0222 |
Count Complete Tree Nodes |
Easy |
| 0225 |
Implement Stack using Queues |
Easy |
| 0226 |
Invert Binary Tree |
Easy |
| 0228 |
Summary Ranges |
Easy |
| 0231 |
Power of Two |
Easy |
| 0232 |
Implement Queue using Stacks |
Easy |
| 0234 |
Palindrome Linked List |
Easy |
| 0242 |
Valid Anagram |
Easy |
| 0243 |
Shortest Word Distance |
Easy |
| 0246 |
Strobogrammatic Number |
Easy |
| 0252 |
Meeting Rooms |
Easy |
| 0257 |
Binary Tree Paths |
Easy |
| 0258 |
Add Digits |
Easy |
| 0263 |
Ugly Number |
Easy |
| 0266 |
Palindrome Permutation |
Easy |
| 0268 |
Missing Number |
Easy |
| 0270 |
Closest Binary Search Tree Value |
Easy |
| 0278 |
First Bad Version |
Easy |
| 0283 |
Move Zeroes |
Easy |
| 0290 |
Word Pattern |
Easy |
| 0292 |
Nim Game |
Easy |
| 0293 |
Flip Game |
Easy |
| 0303 |
Range Sum Query - Immutable |
Easy |
| 0326 |
Power of Three |
Easy |
| 0338 |
Counting Bits |
Easy |
| 0342 |
Power of Four |
Easy |
| 0344 |
Reverse String |
Easy |
| 0345 |
Reverse Vowels of a String |
Easy |
| 0346 |
Moving Average from Data Stream |
Easy |
| 0349 |
Intersection of Two Arrays |
Easy |
| 0350 |
Intersection of Two Arrays II |
Easy |
| 0359 |
Logger Rate Limiter |
Easy |
| 0367 |
Valid Perfect Square |
Easy |
| 0374 |
Guess Number Higher or Lower |
Easy |
| 0383 |
Ransom Note |
Easy |
| 0387 |
First Unique Character in a String |
Easy |
| 0389 |
Find the Difference |
Easy |
| 0392 |
Is Subsequence |
Easy |
| 0401 |
Binary Watch |
Easy |
| 0404 |
Sum of Left Leaves |
Easy |
| 0405 |
Convert a Number to Hexadecimal |
Easy |
| 0408 |
Valid Word Abbreviation |
Easy |
| 0409 |
Longest Palindrome |
Easy |
| 0412 |
Fizz Buzz |
Easy |
| 0414 |
Third Maximum Number |
Easy |
| 0415 |
Add Strings |
Easy |
| 0422 |
Valid Word Square |
Easy |
| 0434 |
Number of Segments in a String |
Easy |
| 0441 |
Arranging Coins |
Easy |
| 0448 |
Find All Numbers Disappeared in an Array |
Easy |
| 0455 |
Assign Cookies |
Easy |
| 0459 |
Repeated Substring Pattern |
Easy |
| 0461 |
Hamming Distance |
Easy |
| 0463 |
Island Perimeter |
Easy |
| 0476 |
Number Complement |
Easy |
| 0482 |
License Key Formatting |
Easy |
| 0485 |
Max Consecutive Ones |
Easy |
| 0492 |
Construct the Rectangle |
Easy |
| 0495 |
Teemo Attacking |
Easy |
| 0496 |
Next Greater Element I |
Easy |
| 0500 |
Keyboard Row |
Easy |
| 0501 |
Find Mode in Binary Search Tree |
Easy |
| 0504 |
Base 7 |
Easy |
| 0506 |
Relative Ranks |
Easy |
| 0507 |
Perfect Number |
Easy |
| 0509 |
Fibonacci Number |
Easy |
| 0511 |
Game Play Analysis I |
Easy |
| 0512 |
Game Play Analysis I |
Easy |
| 0520 |
Detect Capital |
Easy |
| 0521 |
Longest Uncommon Subsequence I |
Easy |
| 0530 |
Minimum Absolute Difference in BST |
Easy |
| 0541 |
Reverse String II |
Easy |
| 0543 |
Diameter of Binary Tree |
Easy |
| 0551 |
Student Attendance Record I |
Easy |
| 0557 |
Reverse Words in a String III |
Easy |
| 0559 |
Maximum Depth of N-ary Tree |
Easy |
| 0561 |
Array Partition |
Easy |
| 0563 |
Binary Tree Tilt |
Easy |
| 0566 |
Reshape the Matrix |
Easy |
| 0572 |
Subtree of Another Tree |
Easy |
| 0575 |
Distribute Candies |
Easy |
| 0577 |
Employee Bonus |
Easy |
| 0584 |
Find Customer Referee |
Easy |
| 0586 |
Customer Placing the Largest Number of Orders |
Easy |
| 0589 |
N-ary Tree Preorder Traversal |
Easy |
| 0590 |
N-ary Tree Postorder Traversal |
Easy |
| 0594 |
Longest Harmonious Subsequence |
Easy |
| 0595 |
Big Countries |
Easy |
| 0596 |
Classes More Than 5 Students |
Easy |
| 0597 |
Friend Requests I: Overall Acceptance Rate |
Easy |
| 0598 |
Range Addition II |
Easy |
| 0599 |
Minimum Index Sum of Two Lists |
Easy |
| 0603 |
Consecutive Available Seats |
Easy |
| 0604 |
Design Compressed String Iterator |
Easy |
| 0605 |
Can Place Flowers |
Easy |
| 0606 |
Construct String from Binary Tree |
Easy |
| 0607 |
Sales Person |
Easy |
| 0610 |
Triangle Judgement |
Easy |
| 0613 |
Shortest Distance in a Line |
Easy |
| 0617 |
Merge Two Binary Trees |
Easy |
| 0619 |
Biggest Single Number |
Easy |
| 0620 |
Not Boring Movies |
Easy |
| 0627 |
Swap Salary |
Easy |
| 0628 |
Maximum Product of Three Numbers |
Easy |
| 0637 |
Average of Levels in Binary Tree |
Easy |
| 0643 |
Maximum Average Subarray I |
Easy |
| 0645 |
Set Mismatch |
Easy |
| 0653 |
Two Sum IV - Input is a BST |
Easy |
| 0657 |
Robot Return to Origin |
Easy |
| 0661 |
Image Smoother |
Easy |
| 0671 |
Second Minimum Node In a Binary Tree |
Easy |
| 0674 |
Longest Continuous Increasing Subsequence |
Easy |
| 0680 |
Valid Palindrome II |
Easy |
| 0682 |
Baseball Game |
Easy |
| 0693 |
Binary Number with Alternating Bits |
Easy |
| 0696 |
Count Binary Substrings |
Easy |
| 0697 |
Degree of an Array |
Easy |
| 0700 |
Search in a Binary Search Tree |
Easy |
| 0703 |
Kth Largest Element in a Stream |
Easy |
| 0704 |
Binary Search |
Easy |
| 0705 |
Design HashSet |
Easy |
| 0706 |
Design HashMap |
Easy |
| 0709 |
To Lower Case |
Easy |
| 0717 |
1-bit and 2-bit Characters |
Easy |
| 0724 |
Find Pivot Index |
Easy |
| 0728 |
Self Dividing Numbers |
Easy |
| 0733 |
Flood Fill |
Easy |
| 0734 |
Sentence Similarity |
Easy |
| 0744 |
Find Smallest Letter Greater Than Target |
Easy |
| 0746 |
Min Cost Climbing Stairs |
Easy |
| 0747 |
Largest Number At Least Twice of Others |
Easy |
| 0748 |
Shortest Completing Word |
Easy |
| 0760 |
Find Anagram Mappings |
Easy |
| 0762 |
Prime Number of Set Bits in Binary Representation |
Easy |
| 0766 |
Toeplitz Matrix |
Easy |
| 0771 |
Jewels and Stones |
Easy |
| 0783 |
Minimum Distance Between BST Nodes |
Easy |
| 0796 |
Rotate String |
Easy |
| 0800 |
Similar RGB Color |
Easy |
| 0804 |
Unique Morse Code Words |
Easy |
| 0806 |
Number of Lines To Write String |
Easy |
| 0812 |
Largest Triangle Area |
Easy |
| 0819 |
Most Common Word |
Easy |
| 0821 |
Shortest Distance to a Character |
Easy |
| 0824 |
Goat Latin |
Easy |
| 0830 |
Positions of Large Groups |
Easy |
| 0832 |
Flipping an Image |
Easy |
| 0836 |
Rectangle Overlap |
Easy |
| 0844 |
Backspace String Compare |
Easy |
| 0859 |
Buddy Strings |
Easy |
| 0860 |
Lemonade Change |
Easy |
| 0867 |
Transpose Matrix |
Easy |
| 0868 |
Binary Gap |
Easy |
| 0872 |
Leaf-Similar Trees |
Easy |
| 0876 |
Middle of the Linked List |
Easy |
| 0883 |
Projection Area of 3D Shapes |
Easy |
| 0884 |
Uncommon Words from Two Sentences |
Easy |
| 0888 |
Fair Candy Swap |
Easy |
| 0892 |
Surface Area of 3D Shapes |
Easy |
| 0896 |
Monotonic Array |
Easy |
| 0897 |
Increasing Order Search Tree |
Easy |
| 0905 |
Sort Array By Parity |
Easy |
| 0908 |
Smallest Range I |
Easy |
| 0914 |
X of a Kind in a Deck of Cards |
Easy |
| 0917 |
Reverse Only Letters |
Easy |
| 0922 |
Sort Array By Parity II |
Easy |
| 0925 |
Long Pressed Name |
Easy |
| 0929 |
Unique Email Addresses |
Easy |
| 0933 |
Number of Recent Calls |
Easy |
| 0938 |
Range Sum of BST |
Easy |
| 0941 |
Valid Mountain Array |
Easy |
| 0942 |
DI String Match |
Easy |
| 0944 |
Delete Columns to Make Sorted |
Easy |
| 0953 |
Verifying an Alien Dictionary |
Easy |
| 0961 |
N-Repeated Element in Size 2N Array |
Easy |
| 0965 |
Univalued Binary Tree |
Easy |
| 0976 |
Largest Perimeter Triangle |
Easy |
| 0977 |
Squares of a Sorted Array |
Easy |
| 0989 |
Add to Array-Form of Integer |
Easy |
| 0993 |
Cousins in Binary Tree |
Easy |
| 0997 |
Find the Town Judge |
Easy |
| 0999 |
Available Captures for Rook |
Easy |
| 1002 |
Find Common Characters |
Easy |
| 1005 |
Maximize Sum Of Array After K Negations |
Easy |
| 1009 |
Complement of Base 10 Integer |
Easy |
| 1013 |
Partition Array Into Three Parts With Equal Sum |
Easy |
| 1018 |
Binary Prefix Divisible By 5 |
Easy |
| 1021 |
Remove Outermost Parentheses |
Easy |
| 1022 |
Sum of Root To Leaf Binary Numbers |
Easy |
| 1025 |
Divisor Game |
Easy |
| 1030 |
Matrix Cells in Distance Order |
Easy |
| 1037 |
Valid Boomerang |
Easy |
| 1046 |
Last Stone Weight |
Easy |
| 1047 |
Remove All Adjacent Duplicates In String |
Easy |
| 1050 |
Actors and Directors Who Cooperated At Least Three Times |
Easy |
| 1051 |
Height Checker |
Easy |
| 1056 |
Confusing Number |
Easy |
| 1064 |
Fixed Point |
Easy |
