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); } }
