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;}