[NEW] LeetCode Online Judge Questions/Answer List

Note:

This post listed the questions in the same order of leetcode website. 
The links to the answer posts is added for your convenience.

I revisited all the questions again and also have modified/updated analysis and code for many of them. Several easier implementations or easier understanding analysis have been added. 

NEW!!!~ I am starting to add Python Code for the leetcode problems.  

LeetCode Online Judge Questions/Answer List

• Reverse Words in a String

• Evaluate Reverse Polish Notation

• Max Points on a Line

• Sort List

• Insertion Sort List

• LRU Cache

• Binary Tree Postorder Traversal

• Binary Tree Preorder Traversal

• Reorder List

• Linked List Cycle II

• Linked List Cycle

• Word Break II

• Word Break

• Copy List with Random Pointer

• Single Number II

• Single Number

• Candy

• Gas Station

• Clone Graph

• Palindrome Partitioning II

• Palindrome Partitioning

• Surrounded Regions

• Sum Root to Leaf Numbers

• Longest Consecutive Sequence

• Word Ladder II

• Word Ladder

• Valid Palindrome

• Binary Tree Maximum Path Sum

• Best Time to Buy and Sell Stock III

• Best Time to Buy and Sell Stock II

• Best Time to Buy and Sell Stock

• Triangle

• Pascal's Triangle II

• Pascal's Triangle

• Populating Next Right Pointers in Each Node II

• Populating Next Right Pointers in Each Node

• Distinct Subsequences

• Flatten Binary Tree to Linked List

• Path Sum II

• Path Sum

• Minimum Depth of Binary Tree

• Balanced Binary Tree

• Convert Sorted List to Binary Search Tree

• Convert Sorted Array to Binary Search Tree

• Binary Tree Level Order Traversal II

• Construct Binary Tree from Inorder and Postorder Traversal

• Construct Binary Tree from Preorder and Inorder Traversal

• Maximum Depth of Binary Tree

• Binary Tree Zigzag Level Order Traversal

• Binary Tree Level Order Traversal

• Symmetric Tree

• Same Tree

• Recover Binary Search Tree

• Validate Binary Search Tree

• Interleaving String

• Unique Binary Search Trees II

• Unique Binary Search Trees

• Binary Tree Inorder Traversal

• Restore IP Addresses

• Reverse Linked List II

• Subsets II

• Decode Ways

• Gray Code

• Merge Sorted Array

• Scramble String   (Difficlut problem, 3D DP might work)

• Partition List

• Maximal Rectangle

• Largest Rectangle in Histogram

• Remove Duplicates from Sorted List II

• Remove Duplicates from Sorted List

• Search in Rotated Sorted Array II

• Remove Duplicates from Sorted Array II

• Word Search

• Subsets

• Combinations

• Minimum Window Substring

• Sort Colors

• Search a 2D Matrix

• Set Matrix Zeroes

• Edit Distance

• Simplify Path

• Climbing Stairs

• Sqrt(x)

• Text Justification

• Plus One

• Valid Number

• Add Binary

• Merge Two Sorted Lists

• Minimum Path Sum

• Unique Paths II

• Unique Paths

• Rotate List

• Permutation Sequence

• Spiral Matrix II

• Length of Last Word

• Insert Interval

• Merge Intervals

• Jump Game

• Spiral Matrix

• Maximum Subarray

• N-Queens II

• N-Queens

• Pow(x, n)

• Anagrams

• Rotate Image

• Permutations II

• Permutations

• Jump Game II

• Wildcard Matching

• Multiply Strings

• Trapping Rain Water

• First Missing Positive

• Combination Sum II

• Combination Sum

• Count and Say

• Sudoku Solver

• Valid Sudoku

• Search Insert Position

• Search for a Range

• Search in Rotated Sorted Array

• Longest Valid Parentheses

• Next Permutation

• Substring with Concatenation of All Words

• Divide Two Integers

• Implement strStr()

• Remove Element

• Remove Duplicates from Sorted Array

• Reverse Nodes in k-Group

• Swap Nodes in Pairs

• Merge k Sorted Lists

• Generate Parentheses

• Valid Parentheses

• Remove Nth Node From End of List

• Letter Combinations of a Phone Number

• 4Sum

• 3Sum Closest

• 3Sum

• Longest Common Prefix

• Roman to Integer

• Integer to Roman

• Container With Most Water

• Regular Expression Matching

• Palindrome Number

• String to Integer (atoi)

• Reverse Integer

• ZigZag Conversion

• Longest Palindromic Substring

• Add Two Numbers

• Longest Substring Without Repeating Characters

• Median of Two Sorted Arrays

• Two Sum