PAT (Advanced Level) 1069. The Black Hole of Numbers (20)

简单题。

#include<cstdio>
#include<cstring>
#include<cmath>
#include<vector>
#include<map>
#include<stack>
#include<queue>
#include<string>
#include<algorithm>
using namespace std;

int n;
int a[];
int num1,num2;

int f(int num)
{
    memset(a,,sizeof a);
    int tmp=num;
    int z=;
    while(tmp) a[z++]=tmp%,tmp=tmp/;
    num1=,num2=;
    sort(a,a+);
    for(int i=;i<;i++) num1=num1*+a[i];
    for(int i=;i>=;i--) num2=num2*+a[i];
    return num2-num1;
}

int main()
{
    scanf("%d",&n);
    if(f(n)==) printf("%04d - %04d = %04d\n",n,n,);
    else
    {
        while()
        {
            int res=f(n);
            printf("%04d - %04d = %04d\n",num2,num1,res);
            n=res;
            if(n==) break;
        }
    }
    return ;
}