package com.liuzhen.chapter8;

public class ChangeMaking {
    
    public void getChangeMakingN(int[] coinType,int n){
        int[] minNumber = new int[n+1];   //初始化后，所有元素均为0，其中minNumber[0] = 0，表示无须找零
        int[] tempMinJ = new int[n+1];    //tempMinJ[0]在此处无含义
        for(int i = 1;i <= n;i++){
            int j = 0;
            int tempJ = -1;      //用于h获取minNumber[i]最小值中当前新使用的硬币面值数组下标
            int temp = Integer.MAX_VALUE;        //计算当前minNumber[i]最小值，初始化int类型最大值
            while(j < coinType.length && i >= coinType[j]){
                if(minNumber[i-coinType[j]] + 1 < temp){
                    temp = minNumber[i-coinType[j]] + 1;
                    tempJ = j;
                }
                j++;
            }
            minNumber[i] = temp;
            tempMinJ[i] = tempJ;
        }
        
        System.out.println("给定硬币面值种类依次为：");
        for(int i = 0;i < coinType.length;i++)
            System.out.print(coinType[i]+" ");
        
        System.out.println("\n找零大小从1到"+n+"的最少硬币组合数目为：");
        for(int i = 1;i < minNumber.length;i++)
            System.out.print(minNumber[i]+" ");
        
        System.out.println("\n对应找零大小从1到"+n+"新增的硬币数组下标为：");
        for(int i = 1;i < tempMinJ.length;i++)
            System.out.print(tempMinJ[i]+" ");
        
        System.out.println("\n对应找零大小从1到"+n+"新增的硬币数组下标对应的硬币面值为：");
        for(int i = 1;i < tempMinJ.length;i++)
            System.out.print(coinType[tempMinJ[i]]+" ");
        
        System.out.println("\n\n找零大小为"+n+"的硬币组合最少数目为："+minNumber[minNumber.length-1]);
        System.out.print("找零大小为"+n+"的硬币组合最少数目对应的硬币面值依次为：");
        int needN = n;
        int minJ = tempMinJ.length-1;
        while(needN > 0){
            System.out.print(coinType[tempMinJ[minJ]]+" ");
            needN = needN - coinType[tempMinJ[minJ]];
            minJ = needN;
        }
    }
    
    public static void main(String[] args){
        ChangeMaking test = new ChangeMaking();
        int[] coinType = {1,3,4};
        test.getChangeMakingN(coinType, 6);
    }
}

给定硬币面值种类依次为：
1 3 4 
找零大小从1到6的最少硬币组合数目为：
1 2 1 1 2 2 
对应找零大小从1到6新增的硬币数组下标为：
0 0 1 2 0 1 
对应找零大小从1到6新增的硬币数组下标对应的硬币面值为：
1 1 3 4 1 3 

找零大小为6的硬币组合最少数目为：2
找零大小为6的硬币组合最少数目对应的硬币面值依次为：3 3