01背包问题的java界面实现
01背包问题的java界面实现下载地址：http://download.csdn.net/source/2371274
public class BackProblem {
public static void main(String[] args) {
new BackProblemJFrame("背包问题");
}
}
import java.util.StringTokenizer;
public class BackProblemArithmetic {
String backVolume,goodsVolume,goodsWorth;
String bestVolume,group =""; int groupGoodsVolume =0,groupGoodsWorth=0;
BackProblemArithmetic(){
}
//数据有效性的判断
public boolean isNumber(String backVolume, String goodsVolume,String goodsWorth){
boolean effective;
this.backVolume = backVolume;
this.goodsVolume = goodsVolume;
this.goodsWorth = goodsWorth;
//判断背包的容量输入是否有误
try{
Integer.valueOf(this.backVolume);
}
catch(Exception ex){
return effective = false;
}
//物品的价值和物品的质量有效性的判断
String str = this.goodsVolume+","+this.goodsWorth;
if (!this.backVolume.equals("") && !this.goodsVolume.equals("")
&& !this.goodsWorth.equals("")) {
StringTokenizer tokenizer = new StringTokenizer(str, "，, ");
effective = true;
while (tokenizer.hasMoreTokens()) {
try {
Integer.valueOf(tokenizer.nextToken());
} catch (Exception e) {
effective = false;
}
}
//判断物品的价值和物品的质量个数是否一致
tokenizer = new StringTokenizer(this.goodsVolume, "，, ");
int a = tokenizer.countTokens();
tokenizer = new StringTokenizer(this.goodsWorth, "，, ");
int b = tokenizer.countTokens();
if(a!= b) effective = false;
}
else effective = false;
return effective;
}
//背包算法的调用
public void backAnswer(){
int gv[],gw[];//定义数组用于存取goodVolume 和 goodsWorth 的值
int i = 1,c = 0,num = 0;//c背包的容量 ， num 背包中物品的个数
//解析物品质量并保存在gv[]数据中
StringTokenizer tokenizer = new StringTokenizer(goodsVolume, "，, ");
gv = new int[tokenizer.countTokens()+1];//动态的决定数组的长度
while (tokenizer.hasMoreTokens()) {
String d = tokenizer.nextToken();
gv[i] = Integer.valueOf(d);//将字符串转换为整型
i++;
}
//解析物品的价值并保存在gw[]数组中
i = 1;
tokenizer = new StringTokenizer(goodsWorth, "，, ");
num = tokenizer.countTokens();
gw = new int[tokenizer.countTokens()+1];
while (tokenizer.hasMoreTokens()) {
String d = tokenizer.nextToken();
gw[i] = Integer.valueOf(d);//将字符串转换为整型
i++;
}
c = Integer.valueOf(backVolume);//得到背包的容量
//为输出测试可以去掉
System.out.println("C ="+ c +"; num ="+ num);
for( i = 1 ;i<gw.length;i++)
System.out.print("gw"+i+"="+gw[i]+" " );
for( i = 1 ;i<gv.length;i++)
System.out.print("gv"+i+"="+ gv[i]+" " );
System.out.println();
back(c,num,gv,gw);//调用背包算法
}
/*背包算法
* 问题描述：
* 给定n种物品和一背包。物品i的重量是wi，其价值为vi，背包的容量为C。
* 问应如何选择装入背包的物品，使得装入背包中物品的总价值最大?
* 问题解决：
* m[i][j] = max(m(i+1,j),m(i+1,j-Wi)+vi); j>=wi
* m[i][j] = m(i+1,j) ;0<=j<=wi;
*/
public void back(int c,int num,int[] gv,int[] gw){//c背包的容量 ， num 背包中物品的个数 ，gv 物品的质量 ，gw物品的价值
int m[][] = new int[num+1][c+1];//定义一个二维数组存放最优值
int i = 0,j = 0,jmax = 0;
int x[] = new int[num+1];//用于存放物品是否放入的标志 1 放入 ， 0 没有放入
jmax = Math.min(gv[num]-1, c);
for( i = 0 ;i <= c ; i++ )//初始化最后一个数据
{
if( i <= jmax ) {
m[num][i] = 0;
}
else{
m[num][i] =gw[num];
}
}
for(i = num -1 ; i > 0 ; i--){
jmax = Math.min(gv[i]-1,c );//当前i物品不能装入的背包容量
for(j = 0; j <= c; j++ ){
if(j <=jmax ){
m[i][j] = m[i+1][j];
}
else {
m[i][j] = Math.max(m[i+1][j], m[i+1][j-gv[i]]+gw[i]);
}
}
}
bestVolume = String.valueOf(m[1][c]);
//输出测试
for(i = 0 ; i <= num ;i++ ){
for(j = 0;j<=c;j++)
System.out.print(m[i][j]+" ");
System.out.println();
}
System.out.println();
//物品的组合方式
for(i = 1 ; i < num; i++ ){
if(m[i][c] == m[i+1][c] )x[i] = 0;
else {
x[i] =1;
c = c - gv[i];
}
}
if(m[num][c]>0) x[num]=1;
else x[num]=0;
//结果的赋值
for(i = 1; i <= num ;i++){
System.out.print("x["+i+"]="+x[i]+" ");
if(i!=num)
group+=x[i] + ", ";
if(i == num)group+=x[i];
if(x[i]==1){
groupGoodsVolume += gv[i];
groupGoodsWorth += gw[i];
}
}
}
public String getBestVolume() {
return bestVolume;
}
public String getGroup() {
return group;
}
public String getGroupGoodsVolume() {
return String.valueOf(groupGoodsVolume) ;
}
public String getGroupGoodsWorth() {
return String.valueOf(groupGoodsWorth);
}
}
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class BackProblemJFrame extends JFrame implements ActionListener {
private JLabel backVolumeJL,goodsVolumeJL,goodsWorthJL,bestVolumeJL,groupJL,
groupGoodsVolumeJL,groupGoodsWorthJL;
private JTextField backVolumeJTF,goodsVolumeJTF,goodsWorthJTF,bestVolumeJTF,groupJTF,
groupGoodsVolumeJTF,groupGoodsWorthJTF;
private JPanel jp;
private JButton ok,reset;
BackProblemJFrame (String s){
super(s);
backProblemJFrame();
}
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
if(e.getSource()==backVolumeJTF){
goodsVolumeJTF.requestFocusInWindow();
}
else if(e.getSource()==goodsVolumeJTF){
goodsWorthJTF.requestFocusInWindow();
}
else if(e.getSource() == reset ){//重置
backVolumeJTF.setText("");
goodsVolumeJTF.setText("");
goodsWorthJTF.setText("");
bestVolumeJTF.setText("");
groupJTF.setText("");
groupGoodsVolumeJTF.setText("");
groupGoodsWorthJTF.setText("");
}
else if(e.getSource() == goodsWorthJTF||e.getSource() == ok){//确定
BackProblemArithmetic bpa = new BackProblemArithmetic();
String bv = backVolumeJTF.getText() ,gv = goodsVolumeJTF.getText(),gw = goodsWorthJTF.getText();
if(bpa.isNumber(bv,gv,gw)){//如果数字有效
bpa.backAnswer();
bestVolumeJTF.setText(bpa.getBestVolume());
groupJTF.setText(bpa.getGroup());
groupGoodsVolumeJTF.setText(bpa.getGroupGoodsVolume());
groupGoodsWorthJTF.setText(bpa.getGroupGoodsWorth());
}
else {
JOptionPane.showMessageDialog(this,"输入的数据必须是数字且" +
"物品的容量/n物品的价值不能为空！", "警告",
JOptionPane.WARNING_MESSAGE);
}
}
}
private void backProblemJFrame() {
// TODO 主界面方法
this.setLayout(null);//设置为空布局 默认的是边界布局
backVolumeJL = new JLabel("请输入背包的容量：");
backVolumeJL.setBounds(30,5,125,25);
this.add(backVolumeJL);
backVolumeJTF = new JTextField(10);
backVolumeJTF.setBounds(160,5,80,25);
backVolumeJTF.addActionListener(this);
this.add(backVolumeJTF);
goodsVolumeJL = new JLabel("请输入所有物品的质量（个数不限，以逗号隔开）");
goodsVolumeJL.setBounds(5,35,300,25);
this.add(goodsVolumeJL);
goodsVolumeJTF = new JTextField(40);
goodsVolumeJTF.setBounds(10,65,270,25);
goodsVolumeJTF.addActionListener(this);
this.add(goodsVolumeJTF);
goodsWorthJL = new JLabel("请输入物品的价值（以逗号隔开，默认为零）");
goodsWorthJL.setBounds(10,95,300,25);
this.add(goodsWorthJL);
goodsWorthJTF = new JTextField(40);
goodsWorthJTF.setBounds(10,125,270,25);
goodsWorthJTF.addActionListener(this);
this.add(goodsWorthJTF);
ok = new JButton("确 定");
ok.setBounds(10,155,120,25);
ok.addActionListener(this);
this.add(ok);
reset = new JButton("重 置");
reset.setBounds(160,155,120,25);
reset.addActionListener(this);
this.add(reset);
jp = new JPanel();
jp.setBorder(BorderFactory.createTitledBorder("结果"));
jp.setBounds(10,185,270,150);
jp.setLayout(null);
this.add(jp);
bestVolumeJL = new JLabel("最优值：");
bestVolumeJL.setBounds(10,20,70,25);
jp.add(bestVolumeJL);
bestVolumeJTF = new JTextField();
bestVolumeJTF.setBounds(80, 20, 180, 25);
bestVolumeJTF.setEditable(false);
jp.add(bestVolumeJTF);
groupJL = new JLabel("组合方式：");
groupJL.setBounds(10,50,70,25);
jp.add(groupJL);
groupJTF = new JTextField();
groupJTF.setBounds(80,50,180,25);
groupJTF.setEditable(false);
jp.add(groupJTF);
groupGoodsVolumeJL = new JLabel("物品质量：");
groupGoodsVolumeJL.setBounds(10,80,70,25);
jp.add(groupGoodsVolumeJL);
groupGoodsVolumeJTF = new JTextField();
groupGoodsVolumeJTF.setBounds(80,80,180,25);
groupGoodsVolumeJTF.setEditable(false);
jp.add(groupGoodsVolumeJTF);
groupGoodsWorthJL = new JLabel("物品价值：");
groupGoodsWorthJL.setBounds(10,110,70,25);
jp.add(groupGoodsWorthJL);
groupGoodsWorthJTF = new JTextField();
groupGoodsWorthJTF.setBounds(80,110,180,25);
groupGoodsWorthJTF.setEditable(false);
jp.add(groupGoodsWorthJTF);
//界面的设置
Toolkit tk = getToolkit();
Dimension dim = tk.getScreenSize();
this.setResizable(false);
this.setBounds(dim.width/2-150, dim.height/2-200,300,380);
this.setVisible(true);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
}
}