传送门:https://pintia.cn/problem-sets/994805342720868352/problems/994805400954585088
思路:排序
#include <iostream>
#include<bits/stdc++.h>
#define rep(i,a,n) for(int i=a;i<n;i++)
#define sca(x) scanf("%d",&x)
#define sca2(x,y) scanf("%d%d",&x,&y)
#define scl(x) scanf("%lld",&x)
#define scs(x) scanf("%s",x)
#define pri(x) printf("%d\n",x)
#define pri2(x,y) printf("%d %d\n",x,y)
#define prs(x) printf("%s\n",(x))
#define prl(x) printf("%lld\n",x)
#define ll long long
#define PII pair<int,int>
#define eps 1e-6
#define inf 1e17
#define INF 0x3f3f3f3f
using namespace std;
const int maxn=1e6+5;
int dig[maxn];
PII<int,int> pi;
PII<int,int> gao(int n){
pair<int,int>p;
int cnt=0;
for(;cnt<4;cnt++){
dig[cnt]=n%10;
n/=10;
}
sort(dig,dig+cnt);
p.first=dig[3]*1000+dig[2]*100+dig[1]*10+dig[0];
p.second=dig[0]*1000+dig[1]*100+dig[2]*10+dig[3];
return p;
}
int main() {
int n,a,b;
sca(n);
while(1){
pi=gao(n);
a=pi.first,b=pi.second;
n=a-b;
printf("%04d - %04d = %04d\n",a,b,n);
if(n==0||n==6174)break;
}
}