java实现贪心算法（背包问题）

package com.ycit.greedypackage;

import java.util.Arrays;

public class GreedyPackage {
	private int MAX_WEIGHT=150;
	private int [] weights = new int[]{35,30,60,50,40,10,24};
	private int [] values = new int[]{10,40,30,50,35,40,30};
	public void greedypackage(int capacity,int [] wegiht,int[] values){
		int n = wegiht.length;
		double [] r = new double[n];//性价比数组
		int [] index = new int [n]; //存放性价比下标
		for(int i=0;i<n;i++){  //求性价比并初始化
			r[i] = (double)values[i]/weights[i];
			index[i] = i;  //默认排序
		}
		// r[]对性价比进行排序(冒泡)，以及对index[]性价比下标排序
		double temp = 0;
		int x = 0;
		for(int i =0;i<n-1;i++){
			for(int j=i+1;j<n;j++){
				if(r[i]<r[j]){
					temp = r[i];
					r[i] = r[j];
					r[j] = temp;
					x = index[i];
					index[i]=index[j];
					index[j] = x;
				}
			}
		}
		//利用性价比下标的排序 对原数据 wegiht，values 排序
		int[] w1 = new int[n];
		int[] v1 = new int [n];
		for(int i=0;i<n;i++){
			w1[i]=wegiht[index[i]];
			v1[i]=values[index[i]];
		}
		//填充背包
		int [] y = new int[n];
		double maxvalue=0;
		for(int i=0;i<n;i++){
			if(w1[i]<capacity){
				//还可以装得下
				y[i]=1;  //表示该物品已经被装过了
				maxvalue+=v1[i];
				System.out.println("物品:"+w1[i]+"放进了包包");
				capacity = capacity-w1[i];
			}
		}
		//打印背包信息和最大价值
		System.out.println("总共放下的物品有:"+Arrays.toString(y));
		System.out.println("背包里面物品的总价值为:"+maxvalue);		
	}
	public static void main(String[] args) {
		GreedyPackage greedyPackage = new GreedyPackage();
		greedyPackage.greedypackage(greedyPackage.MAX_WEIGHT, greedyPackage.weights,greedyPackage.values);
	}
}