PAT甲题题解-1069. The Black Hole of Numbers (20)-模拟

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按照题目的意思纯模拟一遍就行了

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <string.h>
using namespace std;
const int maxn=;
char str[maxn],str1[maxn],str2[maxn];
int a,b,c;
bool cmp1(char a,char b){
    return a>b;
}
bool cmp2(char a,char b){
    return a<b;
}
int main()
{
    int n;
    scanf("%d",&n);
    sprintf(str,"%04d",n); //输入的n可能小于4位数，要补0
    bool isSame=true;
    for(int i=;i<;i++){
        if(str[i]!=str[i-]){
            isSame=false;
        }
    }
    if(isSame){
        printf("%s - %s = 0000\n",str,str);
    }
    else{
        c=;
        while(c!=){
            //strcpy(str1,str);
            //strcpy(str2,str);
            sort(str,str+,cmp1);
            a=atoi(str);
            sort(str,str+,cmp2);
            b=atoi(str);
            c=a-b;
            printf("%04d - %04d = %04d\n",a,b,c);
            sprintf(str,"%04d",c); //注意填0
        }
    }
    return ;
}