docker-mysql-cluster

基于docker搭了个mysql集群，稍微记一下，
首先是新建mysql主库容

玩一下swoole的websocket

WebSocket是HTML5开始提供的一种在单个TCP连接上进行全双工通讯的协议。WebSocket通信协议于2011年被IETF定为标准RFC 6455，WebSocketAPI被W3C定为标准。
,在web私信，im等应用较多。背景和优缺点可以参看wiki。

环境准备

因为swoole官方还不支持windows，所以需要装下linux,之前都是用ubuntu，
这次就试一下centos7，还是满好看的，虽然虚拟机会默认最小安装，需要在安装
时自己选择带gnome的，当然最小安装也是可以的，只是最后需要改下防火墙。
然后是装下PHP，Nginx什么的，我是用Oneinstack，可以按需安装
给做这个的大大点个赞。

Invert a binary tree

     4
   /   \
  2     7
 / \   / \
1   3 6   9

to

     4
   /   \
  7     2
 / \   / \
9   6 3   1

Trivia:
This problem was inspired by this original tweet by Max Howell:

Google: 90% of our engineers use the software you wrote (Homebrew),
but you can’t invert a binary tree on a whiteboard so fuck off.

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/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    TreeNode* invertTree(TreeNode* root) {
        if(root == NULL) return root;
        TreeNode* temp;
        temp = invertTree(root->left);
        root->left = invertTree(root->right);
        root->right = temp;
        return root;
    }
};

*Longest Substring Without Repeating Characters *

problem

You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.

Input:(2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8

分析（不用英文装逼了）
这个代码是抄来的，链接原作是这位大大。

Reverse Integer

Reverse digits of an integer.

Example1: x = 123, return 321
Example2: x = -123, return -321

Reverse Bits

Reverse bits of a given 32 bits unsigned integer.

For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as 00111001011110000010100101000000).

Number of 1 Bits

Write a function that takes an unsigned integer and returns the number of ’1’ bits it has (also known as the Hamming weight). For example, the 32-bit integer ‘11’ has binary representation 00000000000000000000000000001011, so the function should return 3.

Pcre

Perl Compatible Regular Expressions (PCRE) is a regular
expression C library inspired by the regular expression
capabilities in the Perl programming language, written
by Philip Hazel, starting in summer 1997.

因为最近工作内容的一部分需要做字符串的识别处理，所以就顺便用上了之前在PHP中用过的正则，在C/C++中本身不包含正则库，这里使用的pcre，对MFC开发，在这里提供了静态链接库，在引入lib跟.h文件后即可使用。

problem

Given an array of integers, find two numbers such that they add up to a specific target number.

The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2. Please note that your returned answers (both index1 and index2) are not zero-based.