import java.util.*;
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class ThreadTest {
static int type = 4, num = 10; //定義資源數(shù)目和線程數(shù)目
static int[] resource = new int[type]; //系統(tǒng)資源總數(shù)
//static int[] copyResource = new int[type]; //副本
static Random rand = new Random();
static Bank[] bank = new Bank[num]; //線程組
Bank temp = new Bank();
public void init() {
//初始化組中每個(gè)線程,隨機(jī)填充系統(tǒng)資源總數(shù)
for(int i = 0; i type; i++)
resource[i] = rand.nextInt(10) + 80;
System.out.print("Resource:");
for(int i = 0; i type; i++)
System.out.print(" " + resource[i]);
System.out.println("");
for(int i = 0; i bank.length; i++)
bank[i] = new Bank("#" + i);
}
public ThreadTest4() {
init();
}
class Bank extends Thread {
//銀行家算法避免死鎖
public int[]
max = new int[type], //總共需求量
need = new int[type], //尚需資源量
allocation = new int[type]; //已分配量
private int[]
request = new int[type], //申請(qǐng)資源量
copyResource = new int[type]; //資源副本
private boolean isFinish = false; //線程是否完成
int[][] table = new int[bank.length][type*4]; //二維資源分配表
private void init() {
// 隨機(jī)填充總共、尚需、已分配量
synchronized(resource) {
for(int i = 0; i type; i++) {
max[i] = rand.nextInt(5) + 10;
need[i] = rand.nextInt(10);
allocation[i] = max[i] - need[i];
resource[i] -= allocation[i]; //從系統(tǒng)資源中減去已分配的
}
printer();
for(int i = 0; i type; i++) {
if(resource[i] 0) {
//若出現(xiàn)已分配量超出系統(tǒng)資源總數(shù)的錯(cuò)誤則退出
System.out.println("The summation of Threads' allocations is out of range!");
System.exit(1);
}
}
}
}
public Bank(String s) {
setName(s);
init();
start();
}
public Bank() {
//none
}
public void run() {
try {
sleep(rand.nextInt(2000));
}
catch(InterruptedException e) {
throw new RuntimeException(e);
}
while(true) {
//程序沒(méi)有完成時(shí)一直不斷申請(qǐng)資源
if(askFor() == false) {
try {
sleep(1000);
}
catch(InterruptedException e) {
throw new RuntimeException(e);
}
}
else
tryRequest();
if(noNeed() == true)
break;
}
//休眠一段時(shí)間模擬程序運(yùn)行
try {
sleep(1000);
}
catch(InterruptedException e) {
throw new RuntimeException(e);
}
System.out.println(getName() + " finish!");
synchronized(resource) {
//運(yùn)行結(jié)束釋放占有資源
for(int i = 0; i type; i++) {
resource[i] += allocation[i];
need[i] = allocation[i] = max[i] = 0;
}
}
}
private void printer() {
//打印當(dāng)前資源信息
System.out.print(getName() + " Max:");
for(int i = 0; i type; i++)
System.out.print(" " + max[i]);
System.out.print(" Allocation:");
for(int i = 0; i type; i++)
System.out.print(" " + allocation[i]);
System.out.print(" Need:");
for(int i = 0; i type; i++)
System.out.print(" " + need[i]);
System.out.print(" Available:");
for(int i = 0; i type; i++)
System.out.print(" " + resource[i]);
System.out.println("");
}
private boolean askFor() {
//隨機(jī)產(chǎn)生申請(qǐng)資源量并檢測(cè)是否超標(biāo)
boolean canAsk = false;
for(int i = 0; i type; i++) {
request[i] = rand.nextInt(20);
//防止申請(qǐng)量超過(guò)所需量
if(request[i] need[i])
request[i] = need[i];
}
for(int i = 0; i type; i++) //防止隨機(jī)申請(qǐng)資源全為0
if(request[i] 0)
canAsk = true;
synchronized(resource) {
//鎖住可供資源檢查是否超標(biāo)
for(int i = 0; i type; i++) {
if(request[i] resource[i])
//如果申請(qǐng)資源超過(guò)可供資源則等待一段時(shí)間后重新申請(qǐng)
return false;
}
}
return canAsk;
}
private void tryRequest() {
//創(chuàng)建副本嘗試分配請(qǐng)求
synchronized(resource) {
for(int i = 0; i type; i++)
//依然要防止請(qǐng)求量超出范圍
if(request[i] resource[i])
return;
for(int i = 0; i type; i++) {
//復(fù)制資源量并減去需求量到一個(gè)副本上
copyResource[i] = resource[i];
copyResource[i] -= request[i];
}
System.out.print(getName() + " ask for:");
for(int i = 0; i type; i++)
System.out.print(" " + request[i]);
System.out.println("");
if(checkSafe() == true) {
//如果檢查安全則將副本值賦給資源量并修改占有量和需求量
for(int i = 0; i type; i++) {
resource[i] = copyResource[i];
allocation[i] += request[i];
need[i] -= request[i];
}
System.out.println(getName() + " request succeed!");
}
else
System.out.println(getName() + " request fail!");
}
}
private boolean checkSafe() {
//銀行家算法檢查安全性
synchronized(bank) {
//將線程資源信息放入二維資源分配表檢查安全性,0~type可用資源/type~type*2所需資源/type*2~type*3占有資源/type*3~-1可用+占用資源
for(int i = 0; i bank.length; i++) {
for(int j = type; j type*2; j++) {
table[i][j] = bank[i].need[j%type];
}
for(int j = type*2; j type*3; j++) {
table[i][j] = bank[i].allocation[j%type];
}
}
//冒泡排序按需求資源從小到大排
for(int i = 0; i bank.length; i++) {
for(int j = i; j bank.length-1; j++) {
sort(j, 4);
}
}
//進(jìn)行此時(shí)刻的安全性檢查
for(int i = 0; i type; i++) {
table[0][i] = copyResource[i];
table[0][i+type*3] = table[0][i] + table[0][i+type*2];
if(table[0][i+type*3] table[1][i+type])
return false;
}
for(int j = 1; j bank.length-1; j++) {
for(int k = 0; k type; k++) {
table[j][k] = table[j-1][k+type*3];
table[j][k+type*3] = table[j][k] + table[j][k+type*2];
if(table[j][k+type*3] table[j+1][k+type])
return false;
}
}
}
return true;
}
private void sort(int j, int k) {
//遞歸冒泡排序
int tempNum;
if(table[j][k] table[j+1][k]) {
for(int i = type; i type*2; i++) {
tempNum = table[j][i];
table[j][i] = table[j+1][i];
table[j+1][i] = tempNum;
}
/*temp = bank[j];
bank[j] = bank[j+1];
bank[j+1] = temp;*/
}
else if(table[j][k] == table[j+1][k] k type*2) //此資源量相同時(shí)遞歸下一個(gè)資源量排序并且防止超出范圍
sort(j, k+1);
}
private boolean noNeed() {
//是否還需要資源
boolean finish = true;
for(int i = 0; i type; i++) {
if(need[i] != 0) {
finish = false;
break;
}
}
return finish;
}
}
public static void main(String[] args) {
ThreadTest t = new ThreadTest();
//后臺(tái)線程,設(shè)定程序運(yùn)行多長(zhǎng)時(shí)間后自動(dòng)結(jié)束
new Timeout(30000, "---Stop!!!---");
}
}
package temp;
import sun.misc.Sort;
/**
* @author zengjl
* @version 1.0
* @since 2007-08-22
* @Des java幾種基本排序方法
*/
/**
* SortUtil:排序方法
* 關(guān)于對(duì)排序方法的選擇:這告訴我們,什么時(shí)候用什么排序最好。當(dāng)人們渴望先知道排在前面的是誰(shuí)時(shí),
* 我們用選擇排序;當(dāng)我們不斷拿到新的數(shù)并想保持已有的數(shù)始終有序時(shí),我們用插入排序;當(dāng)給出的數(shù)
* 列已經(jīng)比較有序,只需要小幅度的調(diào)整一下時(shí),我們用冒泡排序。
*/
public class SortUtil extends Sort {
/**
* 插入排序法
* @param data
* @Des 插入排序(Insertion Sort)是,每次從數(shù)列中取一個(gè)還沒(méi)有取出過(guò)的數(shù),并按照大小關(guān)系插入到已經(jīng)取出的數(shù)中使得已經(jīng)取出的數(shù)仍然有序。
*/
public int[] insertSort(int[] data) {
1/11頁(yè)
int temp;
for (int i = 1; i data.length; i++) {
for (int j = i; (j 0) (data[j] data[j - 1]); j--) {
swap(data, j, j - 1);
}
}
return data;
}
/**
* 冒泡排序法
* @param data
* @return
* @Des 冒泡排序(Bubble Sort)分為若干趟進(jìn)行,每一趟排序從前往后比較每?jī)蓚€(gè)相鄰的元素的大?。ㄒ虼艘惶伺判蛞容^n-1對(duì)位置相鄰的數(shù))并在
* 每次發(fā)現(xiàn)前面的那個(gè)數(shù)比緊接它后的數(shù)大時(shí)交換位置;進(jìn)行足夠多趟直到某一趟跑完后發(fā)現(xiàn)這一趟沒(méi)有進(jìn)行任何交換操作(最壞情況下要跑n-1趟,
* 這種情況在最小的數(shù)位于給定數(shù)列的最后面時(shí)發(fā)生)。事實(shí)上,在第一趟冒泡結(jié)束后,最后面那個(gè)數(shù)肯定是最大的了,于是第二次只需要對(duì)前面n-1
* 個(gè)數(shù)排序,這又將把這n-1個(gè)數(shù)中最小的數(shù)放到整個(gè)數(shù)列的倒數(shù)第二個(gè)位置。這樣下去,冒泡排序第i趟結(jié)束后后面i個(gè)數(shù)都已經(jīng)到位了,第i+1趟實(shí)
* 際上只考慮前n-i個(gè)數(shù)(需要的比較次數(shù)比前面所說(shuō)的n-1要?。?。這相當(dāng)于用數(shù)學(xué)歸納法證明了冒泡排序的正確性
import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
import oracle.jdbc.driver.OracleDriver;
public class GenPaperServlet extends HttpServlet
{
Connection conn;
Statement stmt;
ResultSet rs;
int total_question_num;
int total_question_in_paper;
int total_paper_num;
String curr_classid;
public GenPaperServlet()
{
conn = null;
stmt = null;
rs = null;
total_question_num = 0;
total_question_in_paper = 0;
total_paper_num = 0;
curr_classid = "";
}
public void doGet(HttpServletRequest httpservletrequest, HttpServletResponse httpservletresponse)
throws ServletException, IOException
{
httpservletresponse.setContentType("text/html;charset=GBK");
PrintWriter printwriter = httpservletresponse.getWriter();
printwriter.println("htmlhead/headbodycenter");
printwriter.println("請(qǐng)以POST方式提交");
printwriter.println("/center/body/html");
printwriter.close();
public class Excer{
public static void main(String args[])
{
Excer ex=new Excer();
int x=0;
int y=0;
ex.math(x,y);
}
void math(int x,int y){
MyMath mm = new MyMath();
System.out.println("x="+x+" ,y="+y);
System.out.println("x+y="+mm.plus(x,y));
System.out.println("x-y="+mm.minus(x,y));
System.out.println("x*y="+mm.multi(x,y));
System.out.println("x/y="+mm.div(x,y));
}
}
class MyMath
{
int plus(int a,int b)
{
return(a+b);
}
int minus(int a,int b)
{
return(a-b);
}
int multi(int a,int b)
{
return(a*b);
}
float div(int a,int b)
{
return ((float)a/b);
}
}
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