PAT 1069

#include<cstdio>#include<iostream>#include<string>#include<string.h>#include<algorithm>#include<queue>#include<map>#include<set>using namespace std;void intoarray(int n,int num[]){for(int i=0;i<4;i++){num[i]=n%10;n=n/10;}}int atoin(int num[]){int sum=0;for(int i=0;i<4;i++){sum=num[i]+sum*10;}return sum;}bool cmp(int a,int b){return a>b;}int main(){//freopen("input.txt","r",stdin);int n;cin>>n;int num[5];while(1){intoarray(n,num);sort(num,num+4);int min=atoin(num);sort(num,num+4,cmp);int max=atoin(num);    n=max-min;printf("%04d - %04d = %04d\n",max,min,n);if(n==0||n==6174)break;}//freopen("con","r",stdin);system("pause");return 0;}