背包问题

package 二〇一七年三月二十四日;import java.util.Arrays;public class 背包问题 {    public static void main(String args[]) {        double M = 10; // 定义背包容量为10        Goods[] g = new Goods[10]; // 定义10个物品        g[0] = new Goods(2, 1.4); // Goods(容量, 价值)        g[1] = new Goods(1.2, 5);        g[2] = new Goods(2.1, 3);        g[3] = new Goods(2.4, 4);        g[4] = new Goods(1.8, 1.4);        g[5] = new Goods(2.2, 6);        g[6] = new Goods(1.1, 1);        g[7] = new Goods(1.5, 3);        g[8] = new Goods(1.1, 0.9);        g[9] = new Goods(2, 2);        System.out.println("物体未排序前的价值容量比(value/volume)：");        for (Goods e : g) {            System.out.printf("%-8.1f", e.value / e.volume);        }        System.out.println();        System.out.println("物体排序后的价值容量比(value/volume)：");        Arrays.sort(g);        for (Goods e : g) {            System.out.printf("%-8.1f", e.value / e.volume);        }        System.out.println();        double[] x = new double[10]; // 存储每个物品放入背包的程度，0<=x<=1        int i = 0;        while (M != 0 && i < g.length) {            if (g[i].volume <= M) {                x[i] = 1;                M -= g[i].volume;                ++i;            } else {                x[i] = M / g[i].volume;                M = 0;            }        }        System.out.println("贪心策略解决背包放入物品问题：");        for (i = 0; i < 10; ++i)            System.out.printf("#%d:%-5.1f \n", i, x[i]);        System.out.println();    }}class Goods implements Comparable<Goods> {    public double volume = 0;    public double value = 0;    public Goods(double vol, double val) {        volume = vol;        value = val;    }    public int compareTo(Goods other) {        if (value / volume < other.value / other.volume)            return 1;        if (value / volume > other.value / other.volume)            return -1;        return 0;    }}