# Category Archives: 算法

## Leetcode: Min Stack

Design a stack that supports push, pop, top, and retrie… Read More »

## Leetcode: Merge k Sorted Lists

Merge k sorted linked lists and return it as one sorted… Read More »

## Leetcode: LRU Cache

Design and implement a data structure for Least Recentl… Read More »

## Leetcode: Word Ladder II

Question Given two words (beginWord and endWord), and a… Read More »

## Leetcode: Palindrome Number

Problem Leetcode link for this question Determine wheth… Read More »

## Leetcode: String to Integer (atoi)

Problem Leetcode link Implement atoi to convert a strin… Read More »

## Leetcode: Contains Duplicate II

Question Contains Duplicate II Given an array of intege… Read More »

## Leetcode: Integer to Roman

Question: Integer to Roman Given an integer, convert it… Read More »

## LeetCode: Reverse Integer

Previous Post This is the previous post on same questio… Read More »

## LeetCode Problem: Maximum Depth of Binary Tree

Recursively count the depth of tree node. One node&#821… Read More »

## LeetCode Problem: Valid Palindrome

To solving this problem, using two pointer to track the… Read More »

## LeetCode Problem: Pascal’s Triangle II

Follow the algorithm in LeetCode Problem: Pascal’s Tria… Read More »

## LeetCode Problem: Pascal’s Triangle

The problem is simple, each element in the triangle is … Read More »

## 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… Read More »

## Algorithm Problem: In-Place Merge Sort

The original merge sort version will take O(n) space, a… Read More »

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

The code in the previous article LeetCode Problem: Popu… Read More »

## 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… Read More »

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

The ordinary dynamic programing gives our an algorithm … Read More »

## Algoritm Problem: Add Two Unsigned Integers

To add two unsigned integers, A and B, we can exam a bi… Read More »

## 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… Read More »

## Algorithm Problem:Intersection of Sorted Array

Binary search every element of arr1 in arr0, if find, a… Read More »

## LeetCode Problem:Flatten Binary Tree to Linked List

We can notice that in the flattened tree, each sub node… Read More »

## 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… Read More »