leetcode-java

This is my accepted codes in LeetCode. 😀

Problems	Difficulty	Remark
1. Two Sum	Easy	HashMap
2. Add Two Numbers	Medium	LinkedList
3. Longest Substring Without Repeating Characters	Medium	String, HashMap
4. Median of Two Sorted Arrays	Hard	Binary Search
5. Longest Palindromic Substring	Medium	String, Recursion
7. Reverse Integer	Easy
9. Palindrome Number	Easy
11. Container With Most Water	Medium	Two Pointers
12. Integer to Roman	Easy
13. Roman to Integer	Easy
14. Longest Common Prefix	Easy
15. 3Sum	Medium	Two Pointers
16. 3Sum Closest	Medium	Two Pointers
19. Remove Nth Node From End of List	Medium	LinkedList
20. Valid Parentheses	Easy	Stack
21. Merge Two Sorted Lists	Easy	LinkedList, Recursion
22. Generate Parentheses	Medium	String, Recursion, DFS?
23. Merge k Sorted Lists	Hard	LinkedList, Divide and Conquer
24. Swap Nodes in Pairs	Medium	LinkedList, Recursion
25. Reverse Nodes in k-Group	Hard	LinkedList, Recursion
26. Remove Duplicates from Sorted Array	Easy
27. Remove Element	Easy
28. Implement strStr()	Easy	String
30. Substring with Concatenation of All Words	Hard	String
31. Next Permutation	Medium	Counting
32. Longest Valid Parentheses	Hard	Stack
33. Search in Rotated Sorted Array	Medium	Binary Search
39. Combination Sum	Medium	Counting
40. Combination Sum II	Medium	Counting
57. Insert Interval	Hard
74. Search a 2D Matrix	Medium	Binary Search
76. Minimum Window Substring	Hard	String, Two Pointers
77. Combinations	Medium	Counting
94. Binary Tree Inorder Traversal	Medium	Binary Tree
102. Binary Tree Level Order Traversal	Medium	Binary Tree
104. Maximum Depth of Binary Tree	Easy	Binary Tree
110. Balanced Binary Tree	Easy	Binary Tree
111. Minimum Depth of Binary Tree	Easy	Binary Tree
144. Binary Tree Preorder Traversal	Medium	Binary Tree
145. Binary Tree Postorder Traversal	Hard	Binary Tree
167. Two Sum II - Input array is sorted	Easy	HashMap
169. Majority Element	Easy	HashMap
206. Reverse Linked List	Easy	LinkedList
226. Invert Binary Tree	Easy	Binary Tree
229. Majority Element II	Medium	HashMap
412. Fizz Buzz	Easy
458. Poor Pigs	Easy
653. Two Sum IV - Input is a BST	Easy	Binary Tree