五大常用算法——分支限界算法详解及经典例题_分支限界求最优解

import static org.junit.Assert.*;
 
import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;
 
import javax.management.Query;
 
import org.junit.Test;
 
class Node{
    private int curw, curv;
    private int units_i;
    private int[] route;
    Node(){
        route = new int[110];
    }
    public Node(int curw, int curv, int units_i, int[] route) {
        super();
        this.curw = curw;
        this.curv = curv;
        this.units_i = units_i;
        this.route = route;
    }
    public int getCurw() {
        return curw;
    }
    public void setCurw(int curw) {
        this.curw = curw;
    }
    public int getCurv() {
        return curv;
    }
    public void setCurv(int curv) {
        this.curv = curv;
    }
    public int getUnits_i() {
        return units_i;
    }
    public void setUnits_i(int units_i) {
        this.units_i = units_i;
    }
    public int[] getRoute() {
        return route;
    }
    public void setRoute(int[] route) {
        this.route = route;
    }
    
}
 
public class 最小重量设计_分支限界法 {
    
    /*
     * 3 3
     * 3 2  1 4  5 6
     * 1 4  3 2  5 6
     * 5 6  3 2  1 4
     * 10
     * 
     * 答案是5
     */
    private static int w[][];
    private static int c[][];
    private static int n, m, cc;
    private static Scanner cin;
    private static Queue<Node>q;
    static{
        cin = new Scanner(System.in);
        q = new LinkedList<Node>();
    }
 
 
    public static void main(String[] args) {
        System.out.println("请输入部件数目以及供货商数量n和m：");
        n = cin.nextInt();
        m = cin.nextInt();
        w = new int[n][m];
        c = new int[n][m];
        
        System.out.println("n行代表n个部件，每行输入每个供货商供应此部件的重量以及价格：");
        for(int i = 0; i < n; i++){
            for(int j = 0; j < m; j++){
                w[i][j] = cin.nextInt();
                c[i][j] = cin.nextInt();
            }
        }
        System.out.println("请输入不超过的价格p：");
        cc = cin.nextInt();
        q.clear();
        int[] route = new int[110];
        Node e = new Node(0, 0, -1, route);
        q.add(e);
        int ans = Integer.MAX_VALUE;
        while(!q.isEmpty()){
            e = q.poll();
            
            for(int j = 0; j < m; j++){
                int i = e.getUnits_i() + 1;
                if(i >= n){
                    
                    if(e.getCurv() <= cc){
                        if(ans > e.getCurw()){
                            ans = Math.min(ans, e.getCurw());
                            route = e.getRoute();
                        }
                    }
                    continue;
                }
                int curv = e.getCurv() + c[i][j];
                int curw = e.getCurw() + w[i][j];
                
                int[] lastroute = e.getRoute();
                int[] curroute = new int[110];
                for(int k = 0; k <= e.getUnits_i(); k++){
                    curroute[k] = lastroute[k];
                }
                curroute[i] = j;
                
                q.add(new Node(curw, curv, i, curroute));
            }
        }
        if(ans == Integer.MAX_VALUE){
            System.out.println("不能找出总价格不超过 c的最小重量机器的方案");
        }else{
            System.out.println("满足方案的最小重量是：" + ans);
            System.out.println("方案是：");
            for(int j = 0; j < n; j++){
                System.out.print(route[j] + " ");
            }
            
        }
    }
    
    
}