@reus 是的


不过最后测下来，感觉性能都差不多，和 io 有关把，我把 Linux ulimit 调到 10001 也是这个结果，再大我的电脑调不上去了，两者耗时还是差不多

我收回说的这句话，java 只是在第一次跑的时候会比 php 慢，之后多次访问后会快很多

@srx1982
@zgqq


我用 servlet 写了，跑在 Tomcat/9.0.22 上，耗时 0.259 秒，还是比 php 慢，要知道 php7 用的 server 是调试用的，上 php-fpm 会更快,


$ ab -n 1000 -c 1000 "http://localhost:8080/servlet-test-1.0-SNAPSHOT/x.png"
This is ApacheBench, Version 2.3 <$Revision: 1757674 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking localhost (be patient)
Completed 100 requests
Completed 200 requests
Completed 300 requests
Completed 400 requests
Completed 500 requests
Completed 600 requests
Completed 700 requests
Completed 800 requests
Completed 900 requests
Completed 1000 requests
Finished 1000 requests


Server Software:
Server Hostname: localhost
Server Port: 8080

Document Path: /servlet-test-1.0-SNAPSHOT/x.png
Document Length: 70 bytes

Concurrency Level: 1000
Time taken for tests: 0.259 seconds
Complete requests: 1000
Failed requests: 0
Total transferred: 188000 bytes
HTML transferred: 70000 bytes
Requests per second: 3867.48 [#/sec] (mean)
Time per request: 258.566 [ms] (mean)
Time per request: 0.259 [ms] (mean, across all concurrent requests)
Transfer rate: 710.05 [Kbytes/sec] received

Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 1 3.5 0 11
Processing: 1 24 13.6 21 74
Waiting: 1 22 12.5 19 72
Total: 3 26 15.3 21 83

Percentage of the requests served within a certain time (ms)
50% 21
66% 27
75% 32
80% 36
90% 51
95% 59
98% 67
99% 71
100% 83 (longest request)





代码：


import java.io.IOException;
import java.io.OutputStream;
import java.util.Base64;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
* Servlet implementation class XServlet
*/
public class XServlet extends HttpServlet {
private static final long serialVersionUID = 1L;

/**
* @see HttpServlet#HttpServlet()
*/
public XServlet() {
super();
// TODO Auto-generated constructor stub
}

/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setHeader("content-type","image/png");
String onepointpngBase64 = "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVQImWP4////fwAJ+wP9CNHoHgAAAABJRU5ErkJggg==";
OutputStream os = response.getOutputStream();
byte[] decodedValue = Base64.getDecoder().decode(onepointpngBase64);
os.write(decodedValue);
}

/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}

}

画面截屏监控无解

@zjsxwc #12 原文：“动态规划，由于与数组顺序无关于是可以，定义 数组解为 A(XnYm) 其中 X、Y 为数组里数的值，n、m 为数 X、Y 分别出现的次数。于是状态转移方程为 A(Xn)=X*nA(XnYm)=max(X*n-m+A(Ym), Y*m-n+A(Xm))A(XnYmZa)=max(X*n-m-a+A(YmZa), Y*m-n-a+A(XmZa), Z*a-n-m+A(XnYm))...依次类推”


感觉复杂度还是 n^3 等大神解答吧

回复：

动态规划，
由于与数组顺序无关于是可以，定义 数组解为 A(XnYm) 其中 X、Y 为数组里数的值，n、m 为数 X、Y 分别出现的次数。

于是状态转移方程为
A(Xn)=X*n
A(XnYm)=max(X*n-m+A(Ym), Y*m-n+A(Xm))
A(XnYmZa)=max(X*n-m-a+A(YmZa), Y*m-n-a+A(XmZa), Z*a-n-mA(XnYm))
...
依次类推

动态规划，
由于与数组顺序无关于是可以，定义 数组解 A 为 X(n)+ Y(m)+... 其中 X、Y 为数组里数的值，n、m 为数 X、Y 分别出现的次数。

于是状态转移方程为
A(XnYm)=max(X*n-m+A(Ym), Y*m-n+A(Xm))
...
依次类推

楼主这种实习还好吧，难道想去 startup 公司加班吗

微信读书续费，几块钱就能看书，爽的一批

历史遗留问题吧，以前是包分配工作的，报到证也和档案一起走，现在大学生毕业有人不想工作等等，报到证得有个接受单位接受，如果不想工作的话也建议楼主找个公司挂靠下

垃圾微信我都懒得打开看，消息权限都不给它，删不删都一样

perl 是凉了吗，我还在玩 perl

还是用 docker 靠谱

把用户对 html 文本的点击、输入等行为转化为新 html 文本

本质上和编译原理没有区别

安卓的 airdroid 局域网分享摄像头也算视频吗？

手写就是伪代码啊，
面试官不会 care 语法错误，
只要思路关键代码实现就行