1069 The Black Hole of Numbers (20分)

1069 The Black Hole of Numbers (20分)

1. 题目

2. 思路

把输入的数字作为字符串，调用排序算法，求最大最小

3. 注意点

输入的数字的范围是(0, 10⁴), 如果作为字符串处理时要注意前面补0

4. 代码

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;

bool cmp(char a, char b){
	return a>b;
}

int main(){
	int n;
	scanf("%d", &n);
	char a[5];
	sprintf(a, "%04d", n);
	int max, min;
	sort(a, a+4, cmp);
	sscanf(a, "%d", &max);
	sort(a, a+4);
	sscanf(a, "%d", &min);
	if(max == min){
		printf("%04d - %04d = 0000", max, min);
	}else{
		int value = max - min;
		while(value != 6174){
			printf("%04d - %04d = %04d\n", max, min, value);
			sprintf(a, "%04d", value);
			sort(a, a+4, cmp);
			sscanf(a, "%d", &max);
			sort(a, a+4);
			sscanf(a, "%d", &min);
			value = max - min;
		}
		printf("%04d - %04d = %04d", max, min, value);
	}
	return 0;
}