一个计算有关问题

import java.util.Scanner;public class Test {    static class Things{        String name;        int price;                public Things(String name,int price){            this.name = name;            this.price = price;        }    }        static Things[] things = new Things[4];        public static void main(String[] args) {        things[0] = new Things("A",5);        things[1] = new Things("B",3);        things[2] = new Things("C",2);        things[3] = new Things("D",4);        for(int i = 0;i < things.length;i++){            for(int j = i + 1;j < things.length;j++){                if(things[j].price < things[i].price){                    Things temp = things[j];                    things[j] = things[i];                    things[i] = temp;                }            }        }        Scanner scanner = new Scanner(System.in);        int num = 0;        System.out.print("输入总价格: ");        try {            num = scanner.nextInt();        } catch (Exception e) {            System.out.println("error");        }        StringBuffer result = new StringBuffer();        for(int i = 0;i <= num / things[0].price;i++){            if(things[0].price * i == num){                result.append(things[0].name + " * " + i + "\n");            }            for(int j = 0;j <= num / things[1].price;j++){                if(j != 0 &&things[0].price * i + things[1].price * j == num){                    result.append(                        things[0].name + " * " + i + " + " +                         things[1].name + " * " + j + "\n");                }                for(int m = 0;m <= num / things[2].price;m++){                    if(m != 0 && things[0].price * i + things[1].price * j  + things[2].price * m == num){                        result.append(                            things[0].name + " * " + i + " + " +                            things[1].name + " * " + j + " + " +                            things[2].name + " * " + m + "\n");                    }                    for(int n = 0;n <= num / things[3].price;n++){                        if(n != 0 && things[0].price * i + things[1].price * j  +                                 things[2].price * m  + things[3].price * n == num){                            result.append(                                things[0].name + " * " + i + " + " +                                things[1].name + " * " + j + " + " +                                things[2].name + " * " + m + " + " +                                things[3].name + " * " + n + "\n");                        }                    }                }            }        }        System.out.println(result);    }}
------解决方案--------------------
Java code
    public static void test4(int[] array, int begin, int tempVal, int val,List<Integer> result) {        if (tempVal == val) {            System.out.println(result);            return;        }        for (int i = begin; i < array.length; i++) {            if (tempVal < val) {                result.add(array[i]);                tempVal += array[i];                test4(array, i + 1, tempVal, val, result);                tempVal -= result.remove(result.size() - 1);            }        }    }    public static void main(String[] args) {        test4(new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 }, 0, 0, 10,new ArrayList());    }
------解决方案--------------------