## Leetcode: Nested List Weight Sum II

Given a nested list of integers, return the sum of all […]

## Leetcode: Factor Combinations

Numbers can be regarded as product of its factors. For […]

## Leetcode: Binary Search

Given a sorted (in ascending order) integer array nums […]

## Leetcode: Implement Trie (Prefix Tree)

Implement a trie with insert, search, and startsWith me […]

## Leetcode: Min Stack

Design a stack that supports push, pop, top, and retrie […]

## Leetcode: Merge k Sorted Lists

Merge k sorted linked lists and return it as one sorted […]

## Leetcode: Encode and Decode TinyURL

TinyURL is a URL shortening service where you enter a U […]

## Leetcode: LRU Cache

Design and implement a data structure for Least Recentl […]

Question Given two words (beginWord and endWord), and a […]

## Leetcode: Valid Number

Question Validate if a given string is numeric. Some ex […]

## Leetcode: Palindrome Number

Problem Leetcode link for this question Determine wheth […]

## Leetcode: String to Integer (atoi)

Problem Leetcode link Implement atoi to convert a strin […]

## Leetcode: Contains Duplicate II

Question Contains Duplicate II Given an array of intege […]

## Leetcode: Integer to Roman

Question: Integer to Roman Given an integer, convert it […]

## LeetCode: Reverse Integer

Previous Post This is the previous post on same questio […]

## LeetCode: ZigZag Conversion

Previous post This is the old post on this question, us […]

## LeetCode Problem: Maximum Depth of Binary Tree

Recursively count the depth of tree node. One node&#821 […]

## LeetCode Problem: Valid Palindrome

To solving this problem, using two pointer to track the […]

## LeetCode Problem: Pascal’s Triangle II

Follow the algorithm in LeetCode Problem: Pascal’s Tria […]

## LeetCode Problem: Pascal’s Triangle

The problem is simple, each element in the triangle is […]

## Algorithm Problem: Find Out the Minimum Number that Great or Equal to a Given Number In BST

Given a BST and a Number k, find out the minimum number […]

## Algorithm Problem: In-Place Merge Sort

The original merge sort version will take O(n) space, a […]

## LeetCode Problem: Populating Next Right Pointers in Each Node II

The code in the previous article LeetCode Problem: Popu […]

## LeetCode Problem: Populating Next Right Pointers in Each Node, Level traversal of binary tree

It’s easy to doing this by using a queue, doing a […]

## Algorithm Problem: Longest Non-Descending Sub Array or Logest Increasing Subarray, Dynamic programming

The ordinary dynamic programing gives our an algorithm […]

## Algoritm Problem: Add Two Unsigned Integers

To add two unsigned integers, A and B, we can exam a bi […]

## Algorithm Problems: Two Sum

Manage two pointer to the array, one from the front, mo […]

## Algorithm Problem:Swap the left and right sub-tree in a binary tree without recursion

Just swap the tree nodes’ left and right child, i […]

## Algorithm Problem:Intersection of Sorted Array

Binary search every element of arr1 in arr0, if find, a […]

## LeetCode Problem:Flatten Binary Tree to Linked List

We can notice that in the flattened tree, each sub node […]

## Algorithm Sqrt for Double

The binary divide is straight forward solution, but som […]

## Algorithm Problem: Coins,Integer Bag Problem using Dynamic Programming

We can calculate the result by dynamic programming. Whe […]

## LeetCode Problem:Distinct Subsequences

(2013-1-5更新了动态规划版本，见下面) 这题有点复杂，一开始拿到都不知道怎么下手。 尝试的路径是： 1 […]