$AC$代码：
```cpp
#include <bits/stdc++.h>
using namespace std;
int gcd(int m, int n) {
return m==n?m:gcd(max(m,n)-min(m,n),min(m,n));
}
int main() {
int a[4];
cin>>a[1]>>a[2]>>a[3];
int max=a[1];
for(int i=2; i<=3; i++)
if(a[i]>max)
max=a[i];
int min=a[1];
for(int i=2; i<=3; i++)
if(a[i]<min && a[i]!=max)
min=a[i];
int x,y;
x=max/gcd(min,max);
y=min/gcd(min,max);
cout<<y<<"/"<<x;
return 0;
}
```
by Eason_AC @ 2018-12-01 17:18:40
跳出循环时d=0，然后就RE了
by Hope2075 @ 2018-12-01 17:19:37
@[i_m_a_](/space/show?uid=86649) 你跳出循环是d=0,然后又拿a除以d,除以0当然RE咯
by SfumatoCannon_ @ 2018-12-01 17:23:29
@[i_m_a_](/space/show?uid=86649) 你直接输出e和f不就行了
by SfumatoCannon_ @ 2018-12-01 17:24:19
给一份WA代码……
（注意：去掉输出中间变量还是WA）
```cpp
#include<bits/stdc++.h>
using namespace std;
int main()
{
long long a,b,c,d,e,f;
cin>>a>>b>>c;
if(a>c){e=a;f=c;};
if(a==c){e=a;f=c;};
if(a<c){e=c;f=a;};
//cout<<f;
d=e%f;
while(d!=0)
{
e=f;
f=d;
d=e%f;
cout<<f<<endl;
}
cout<<d<<endl;
a=a/f;
c=c/f;
cout<<a<<"/"<<c;
return 0;
}
```
by Hope2075 @ 2018-12-01 17:24:20
@[SfumatoCannon_](/space/show?uid=125429)
这不是我发的讨论……
by Hope2075 @ 2018-12-01 17:24:46
~~~~蒟蒻大悟~~~~
by KasuganoSora @ 2018-12-01 17:25:07
@[i_m_a_](/space/show?uid=86649) @错人了，尴尬
by SfumatoCannon_ @ 2018-12-01 17:25:34
需要对三个数排序
~~int a[3]~~
~~sort(a,a+3)~~
by Hope2075 @ 2018-12-01 17:26:38
爆零了······```cpp
#include<bits/stdc++.h>
using namespace std;
int main()
{
long long a,b,c,d,e,f;
cin>>a>>b>>c;
if(a>c){e=a;f=c;}
if(a==c){e=a;f=c;}
if(a<c){e=c;f=a;}
d=e%f;
while(d!=0)
{
e=f;
f=d;
d=e%f;
}
cout<<e<<"/"<<f;
return 0;
}
```
by KasuganoSora @ 2018-12-01 17:28:00