```cpp
#include<bits/stdc++.h>
using namespace std;
int gcd(int x,int y){
if(y==0) return x;
return gcd(y,x%y);
}
int a[105];
int main(){
cin>>a[1]>>a[2]>>a[3];
sort(a+1,a+4);
int t=gcd(a[1],a[3]);
a[1]/=t;
a[3]/=t;
cout<<a[1]<<"/"<<a[3];
return 0;
}
```
by lzm0107 @ 2023-11-22 20:58:07
开了O2以后函数不能没有返回值(void除外)
gcd函数最后一行改成
```cpp
return gcd(y, x % y);
```
即可(而且原本好像gcd就应该加上return)
by C20220403 @ 2023-11-22 21:01:06