@[李恪佳](/user/63931) 非void类函数都是要返回的
by Dimly_dust @ 2020-07-20 16:28:16
@[Dimly_dust](/user/316896) 谢谢，改了，但还WA了两个点，你能帮我看看吗
```cpp
#include<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;
int n,m,s,t,x1,y1,x2,y2,mmin=2147483647,fa[5005];
struct node
{
int x,y,v;
}a[5005];
int find(int x)
{
if(fa[x]==x)return x;
else return fa[x]=find(fa[x]);
}
void bcj(int x,int y)
{
int x1=find(x),y1=find(y);
if(x1!=y1)fa[x1]=y1;
}
bool pd(int x,int y)
{
int x1=find(x),y1=find(y);
if(x1!=y1)return true;
else return false;
}
int gcd(int x,int y)
{
while(x%y)
{
int z=x%y;
x=y;
y=z;
}
return y;
}
bool cmp(node x,node y)
{
return x.v<y.v;
}
int main()
{
scanf("%d%d",&n,&m);
for(int i=1;i<=m;i++)
scanf("%d%d%d",&a[i].x,&a[i].y,&a[i].v);
scanf("%d%d",&s,&t);
sort(a+1,a+m+1,cmp);
for(int i=1;i<m;i++)
{
int ok=0;
for(int j=1;j<=n;j++)
fa[j]=j;
bcj(a[i].x,a[i].y);
for(int j=i;j<=m;j++)
{
if(pd(a[j].x,a[j].y))bcj(a[j].x,a[j].y);
if(!pd(s,t)){ok=j;break;}
}
if(ok!=0&&a[ok].v-a[i].v<mmin)
{
x1=a[i].v;
y1=a[ok].v;
mmin=a[ok].v-a[i].v;
}
}
if(mmin==2147483647)cout<<"IMPOSSIBLE";
else
{
x2=x1/gcd(x1,y1);
y2=y1/gcd(x1,y1);
if(y2%x2==0)cout<<y2/x2;
else cout<<y2<<"/"<<x2;
}
}
```
by LikeJ @ 2020-07-20 16:32:22
@[Dimly_dust](/user/316896) 我们机房有个巨佬帮我改AC了
```cpp
#include<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;
int n,m,s,t,x1,y1,x2,y2,fa[5005];
double mmin=2147483647;
struct node
{
int x,y,v;
}a[5005];
int find(int x)
{
if(fa[x]==x)return x;
else return fa[x]=find(fa[x]);
}
void bcj(int x,int y)
{
int x1=find(x),y1=find(y);
if(x1!=y1)fa[x1]=y1;
}
bool pd(int x,int y)
{
int x1=find(x),y1=find(y);
if(x1!=y1)return true;
else return false;
}
int gcd(int x,int y)
{
while(x%y)
{
int z=x%y;
x=y;
y=z;
}
return y;
}
bool cmp(node x,node y)
{
return x.v<y.v;
}
int main()
{
scanf("%d%d",&n,&m);
for(int i=1;i<=m;i++)
scanf("%d%d%d",&a[i].x,&a[i].y,&a[i].v);
scanf("%d%d",&s,&t);
sort(a+1,a+m+1,cmp);
for(int i=1;i<=m;i++)
{
int ok=0;
for(int j=1;j<=n;j++)
fa[j]=j;
bcj(a[i].x,a[i].y);
for(int j=i;j<=m;j++)
{
if(pd(a[j].x,a[j].y))bcj(a[j].x,a[j].y);
if(!pd(s,t)){ok=j;break;}
}
if(ok!=0&&double(a[ok].v)/a[i].v<mmin)
{
x1=a[i].v;
y1=a[ok].v;
mmin=double(a[ok].v)/a[i].v;
}
}
if(mmin==2147483647)cout<<"IMPOSSIBLE";
else
{
x2=x1/gcd(x1,y1);
y2=y1/gcd(x1,y1);
if(x2==1||y2==1)cout<<y2/x2;
else cout<<y2<<"/"<<x2;
}
}
```
谢谢你们
by LikeJ @ 2020-07-20 16:44:14
@[李恪佳](/user/63931) Ok
by Dimly_dust @ 2020-07-20 16:44:48
谢谢大家
by LikeJ @ 2020-07-20 16:53:19