1069. The Black Hole of Numbers (20)

#include <iostream>
#include <string.h>
#include <algorithm>using namespace std;int cmp(char a, char b)
{return a > b;
}int main()
{int num[2];scanf("%d", &num[0]);char s[5];while(1){sprintf(s, "%04d", num[0]);sort(s, s + 4, cmp);sscanf(s, "%d", &num[0]);printf("%s - ", s);sort(s, s + 4);printf("%s = ", s);sscanf(s, "%d", &num[1]);num[0] -= num[1];printf("%04d\n", num[0]);if(num[0] == 0 || num[0] == 6174){break;}}system("pause");return 0;
}