jiakai0419-CSDN博客

原创 Linux ps 札记

ps命令：显示系统当前进程的快照ps 显示当前终端启动的进程ps u以用户为主格式来显示进程状况ps a显示现行终端所有用户的进程（相当于去掉了仅当前用户的限制）ps x显示当前用户启动的进程（相当于去掉了现行终端的限制）这下终于知道ps aux中a、u、x都起到什么作用了。注：现行终端指，此时所有连接在主机上

2013-07-10 21:03:44 498

原创 serialize simple demo (ObjectInputStream/ObjectOutputStream)

import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;public class ObjectSerializeUtil { public static void write(Str

2013-02-21 23:37:34 332

原创 deflate and inflate simple demo (ZipInputStream/ZipOutputStream)

import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.util.zip.Adler32;import java

2013-02-20 17:26:13 595

原创 Argument list too long

昨天碰见了一个case,一个脚本执行失败。经过排查，原因是因为shell命令,参数过长(Argument list too long)因为时间有限，也没查阅很多资料，只是跟一个懂Linux的朋友咨询了一些问题。Linux里面有个参数ARG_MAX,可以通过getconf ARG_MAX 这个命令来查询他的值。我这个系统上值是131

2012-10-16 14:45:06 489

原创 Java IO使用手册

BufferedReader读一行，怎么算一行？行末的标志是：(1)'\n' (2) '\r' (3) "\r\n" (4) EOF而且这个方法不会把 \r \n读进字符串中，但是会吃掉缓冲区的\r \n.

2012-09-11 15:25:40 350

原创浅谈classpath

classpath:即Java进程寻找资源的路径。简而言之，Java进程在寻找资源的时候会从classpath中的路径去搜索。在我看来classpath不应该是一个静态的概念，应该由进程的角度去理解。每一个JVM进程都有自己的classpath参数。我们可以通过运行时来设置，如 java -classpath "路径" "xxx"回头来思考一个问题，用IDE运行

2012-07-23 11:31:12 503

转载 JVM 指令集

指令码助记符说明0x00 nop 什么都不做0x01 aconst_null 将null推送至栈顶0x02 iconst_m1 将int型-1推送至栈顶0x03 iconst_0 将int型0推送至栈顶0x04 iconst_1 将int型1推送至栈顶0x05 iconst_2 将int型2推送至栈顶0x06 iconst_3 将int型3推送

2012-07-17 20:35:23 374

原创 hdu 1262( 筛选法求素数 )

寻找素数对Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 4267 Accepted Submission(s): 2084Problem Description哥德巴赫猜想大家都知道一点吧.我们现在不

2012-05-29 16:43:22 448

原创 poj 2312( 搜索 )

Battle CityTime Limit: 1000MS Memory Limit: 65536KTotal Submissions: 5789 Accepted: 1913DescriptionMany of us had played the game "Battle city" in our childhood

2012-05-24 16:19:02 1079

原创 poj 2251( 搜索 )

Dungeon MasterTime Limit: 1000MS Memory Limit: 65536KTotal Submissions: 11163 Accepted: 4308DescriptionYou are trapped in a 3D dungeon and need to find the quic

2012-05-19 13:59:53 338

原创 poj 1321( 搜索 )

棋盘问题Time Limit: 1000MS Memory Limit: 10000KTotal Submissions: 14396 Accepted: 7100Description在一个给定形状的棋盘（形状可能是不规则的）上面摆放棋子，棋子没有区别。要求摆放时任意的两个棋子不能放在棋盘中的同一行或者同一列，请编程

2012-05-18 11:23:33 280

原创 poj 3414( 搜索 )

PotsTime Limit: 1000MS Memory Limit: 65536KTotal Submissions: 6517 Accepted: 2732 Special JudgeDescriptionYou are given two pots, having the volume of A and

2012-05-17 15:53:35 311

原创 poj 3009( 搜索 )

Curling 2.0Time Limit: 1000MS Memory Limit: 65536KTotal Submissions: 6547 Accepted: 2724DescriptionOn Planet MM-21, after their Olympic games this year, curling

2012-05-15 21:21:00 636

原创 poj 3278( 搜索 )

Catch That CowTime Limit: 2000MS Memory Limit: 65536KTotal Submissions: 29250 Accepted: 9000DescriptionFarmer John has been informed of the location of a fugiti

2012-05-14 21:02:51 309

原创 poj 2488( 搜索 )

A Knight's JourneyTime Limit: 1000MS Memory Limit: 65536KTotal Submissions: 19442 Accepted: 6549DescriptionBackground The knight is getting bored of seeing th

2012-05-14 19:32:55 305

原创排序算法札记(待续)

冒泡排序属于交换排序稳定排序最佳情况：正序，只需n-1比较最佳时间复杂度：O(n)最差情况：逆序最差时间复杂度：O(n^2)平均时间复杂度：O(n^2)空间复杂度：O(1)Demovoid bubbleSort(int a[],int n){ int i,j,temp; for( i = n; i > 1; i-- ){ fo

2012-05-04 20:36:31 300

原创 poj 2349(最小生成树)

Arctic NetworkTime Limit: 2000MS Memory Limit: 65536KTotal Submissions: 5359 Accepted: 1901DescriptionThe Department of National Defence (DND) wishes to connect

2012-05-04 13:15:58 429

原创 poj 1789(最小生成树)

Truck HistoryTime Limit: 2000MS Memory Limit: 65536KTotal Submissions: 11665 Accepted: 4376DescriptionAdvanced Cargo Movement, Ltd. uses trucks of different typ

2012-05-04 10:22:25 309

原创 poj 2421(最小生成树)

Constructing RoadsTime Limit: 2000MS Memory Limit: 65536KTotal Submissions: 15536 Accepted: 6291DescriptionThere are N villages, which are numbered from 1 to N,

2012-05-03 17:43:17 414

原创 poj 2485(最小生成树 Prim)

HighwaysTime Limit: 1000MS Memory Limit: 65536KTotal Submissions: 15109 Accepted: 7034DescriptionThe island nation of Flatopia is perfectly flat. Unfortunately,

2012-05-03 15:45:04 472

原创 poj 1258(最小生成树 Kruskal)

Agri-NetTime Limit: 1000MS Memory Limit: 10000KTotal Submissions: 26390 Accepted: 10410DescriptionFarmer John has been elected mayor of his town! One of his cam

2012-05-03 12:39:34 407

原创 hdu 1709(普通型母函数)

The BalanceTime Limit: 1000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3249 Accepted Submission(s): 1294Problem DescriptionNow you are as

2012-05-01 20:58:46 492

原创 hdu 1171(普通型母函数)

Big Event in HDUTime Limit: 10000/5000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 11501 Accepted Submission(s): 4026Problem DescriptionNowaday

2012-05-01 17:33:31 338

原创 hdu 1085(普通型母函数)

Holding Bin-Laden Captive!Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 8592 Accepted Submission(s): 3856Problem Description

2012-05-01 15:47:48 333

原创 hdu 1398(普通型母函数)

Square CoinsTime Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 4675 Accepted Submission(s): 3166Problem DescriptionPeople in Sil

2012-05-01 15:05:02 307

原创 hdu 1028(普通型母函数)

Ignatius and the Princess IIITime Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 6546 Accepted Submission(s): 4625Problem Description

2012-05-01 13:33:48 399

原创 hdu 1166(树状数组)

敌兵布阵Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 13732 Accepted Submission(s): 5975Problem DescriptionC国的死对头A国这段时间正在进行军事演习

2012-04-30 09:28:29 393

原创 poj 1308(并查集)

Is It A Tree?Time Limit: 1000MS Memory Limit: 10000KTotal Submissions: 14319 Accepted: 4944DescriptionA tree is a well-known data structure that is either empty

2012-04-29 13:53:56 269

原创 poj 1182(并查集)

食物链Time Limit: 1000MS Memory Limit: 10000KTotal Submissions: 28414 Accepted: 8257Description动物王国中有三类动物A,B,C，这三类动物的食物链构成了有趣的环形。A吃B， B吃C，C吃A。现有N个动物，以1－N编号。每个动物

2012-04-28 00:02:47 243

原创 poj 2524(并查集链表实现)

Ubiquitous ReligionsTime Limit: 5000MS Memory Limit: 65536KTotal Submissions: 16643 Accepted: 8050DescriptionThere are so many different religions in the world

2012-04-27 23:45:49 504

原创 poj 2524(并查集)

Ubiquitous ReligionsTime Limit: 5000MS Memory Limit: 65536KTotal Submissions: 16636 Accepted: 8044DescriptionThere are so many different religions in the world

2012-04-27 14:26:19 223

原创 poj 1703(并查集另一种解法)

Find them, Catch themTime Limit: 1000MS Memory Limit: 10000KTotal Submissions: 20517 Accepted: 6071DescriptionThe police office in Tadu City decides to say ends

2012-04-27 13:41:57 442

原创 poj 2492(并查集)

A Bug's LifeTime Limit: 10000MS Memory Limit: 65536KTotal Submissions: 20474 Accepted: 6657DescriptionBackground Professor Hopper is researching the sexual be

2012-04-26 21:20:16 487

原创 poj 2236(并查集)

Wireless NetworkTime Limit: 10000MS Memory Limit: 65536KTotal Submissions: 11583 Accepted: 4926DescriptionAn earthquake takes place in Southeast Asia. The ACM (

2012-04-26 12:10:29 298

原创 poj 1988(并查集)

Cube StackingTime Limit: 2000MS Memory Limit: 30000KTotal Submissions: 13788 Accepted: 4650Case Time Limit: 1000MSDescriptionFarmer John and Betsy are pla

2012-04-25 21:41:32 272

原创 poj 1703(并查集)

Find them, Catch themTime Limit: 1000MS Memory Limit: 10000KTotal Submissions: 20441 Accepted: 6052DescriptionThe police office in Tadu City decides to say ends

2012-04-25 16:38:46 465

原创 poj 1611(并查集)

The SuspectsTime Limit: 1000MS Memory Limit: 20000KTotal Submissions: 14238 Accepted: 6761DescriptionSevere acute respiratory syndrome (SARS), an atypical pneum

2012-04-24 14:05:49 252

原创突破private的防线

Java的封装性，有两种含义。把数据和操作封装在一起，形成类。给字段和方法设置访问权限，限制访问。众所周知如果给某个字段或者方法设置private权限，那么该字段或者方法在类外就不可见了，也不可访问了。但是其实Java还是给private留了后门。我们可以通过RTTI，反射。来在类外访问某类的private字段或者方法。Demo

2012-03-11 02:27:47 416

原创字符编码问题之手动转码并不万能

引言相信大家在最开始接触web的时候，因为Tomcat服务器默认的URIEncoding是ISO8859-1。应该产生过中文乱码问题，某些前辈就会告诉你，可以手动转码。new String(str.getBytes("IOS8859-1"),"gbk");这句话大家应该不陌生，如果页面编码方式是gbk，Tomcat URIEncoding是ISO8859-1。这样编

2012-03-05 19:01:31 2797 5

原创 Spring-AOP配置(学习笔记)

AOP conceptsAspect:切面Join point:织入点Advice:建议Pointcut:织入点的集合Target object:目标对象AOP proxy:代理对象Weaving:编织@AspectJ or XML for Spring AOP?Spring对AOP的配置，可以选择XML或

2012-03-04 15:20:01 530

SPFA算法的优化及应用

ACM算法分类图

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