MENU

第六届蓝桥杯Java B——九数组分数

March 13, 2019 • Read: 2600 • 算法阅读设置

1,2,3...9 这九个数字组成一个分数,其值恰好为1/3,如何组法?

下面的程序实现了该功能,请填写划线部分缺失的代码。

public class A {
    public static void test(int[] x) {
        int a = x[0] * 1000 + x[1] * 100 + x[2] * 10 + x[3];
        int b = x[4] * 10000 + x[5] * 1000 + x[6] * 100 + x[7] * 10 + x[8];
        if (a * 3 == b)
            System.out.println(a + " " + b);
    }

    public static void f(int[] x, int k) {
        if(k >= x.length){
            test(x);
            return;
        }
        
        for(int i = k; i < x.length; i++){
            {int t=x[k]; x[k]=x[i]; x[i]=t;}
            f(x,k+1);
            int t = x[i]; x[i] = x[k]; x[k] = t;    // 填空
        }
    }

    public static void main(String[] args) {
        int[] x = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
        f(x, 0);
    }
}
Archives Tip
QR Code for this page
Tipping QR Code