Algorithm

I like to brush leetcode, it is a way of my pastime.

I really enjoy it, I will always update it.

🎉🎉🎉 Started at 2018.9.11

🙈🙈🙈Restart at 2019.01.14

directory

• leetcode
  • Array
  • LinkedList
  • String
  • Tree
  • math
  • DP
  • SQL

leetcode

Array

Problem	Solution	Time	Difficulty	Note
26.Remove Duplicates from Sorted Array	java	O(N)	Easy
27.Remove Element	java	O(N)	Easy
35.Search Insert Position	java	O(N)	Easy
53.Maximum Subarray	java		Easy
66.Plus One	java	O(N)	Easy
1.Two Sum	java
14.Longest Common Prefix	java	O(N)	Easy	😩第一个元素范围

LinkedList

Problem	Solution	Time	Difficulty	Note
21.Merge Two Sorted Lists	java	O(N)	Easy

String

Problem	Solution	Time	Difficulty	Note
28.Implement strStr()	java	O(N)||O(1)	Easy
58.Length of Last Word	java		Easy
20.Valid Parentheses	java	O(N)	Easy	🤣最终的返回为stack.isEmpty()
125.Valid Palindrome	java		Easy	API:isLetterOrDigit() toLowerCase()

Tree

Problem	Solution	Time	Difficulty	Note
100.Same Tree	java	O(N)	Easy

Math

Problem	Solution	Time	Difficulty	Note
7.Reverse Integer	java		Easy
9.Palindrome Number	java	O(N)	Easy
136.Single Number	java	O(N)	Easy	🤣Bit Manipulation(位运算)才是解决王道
171Excel Sheet Column Number	java	O(N)	Easy	🙈打脸，Restart的第一道题，思维迟钝了，以后每天一道～坚持住！
168. Excel Sheet Column Title	java		Easy	对比参照No171，两者题目反过来，思维反过来处理即可。

DP

Problem	Solution	Time	Difficulty	Note
70.Climbing Stairs	java	O(N)	Easy	😇DP初步讲解 & 讲解

SQL

Problem	Solution	Time	Difficulty	Note
175. Combine Two Tables	Sql		Easy	😑😑😑很久没写sql了，忘了差不多了，是时候捡起来了～！