C++ :

#include <cstdio>
#include <cstring>
#include <queue>
 
using namespace std;
 
struct Edge{
    int v,w,nx;
};
 
Edge edge[100001];
int headlist[101],n,m,st,en,q,b,t,a,map[101][101]={0};
double ans[101][101],dx[101][1001];
 
struct Point{
    int id,sw;
};
 
queue<Point> que;bool ex[101][1001]={0};
Point in,temp;
 
void spfa()
{
    for(int i=1;i<=n;i++)
        for(int j=1;j<=n;j++)
            dx[i][j]=100000000.0;
    dx[st][0]=0;
    in.id=st;
    in.sw=0;
    que.push(in);
    while(!que.empty())
    {
        in=que.front();
        que.pop();ex[in.id][in.sw]=0;
        for(int i=headlist[in.id];i!=-1;i=edge[i].nx)
        {
            if(dx[edge[i].v][in.sw+1]>dx[in.id][in.sw]+edge[i].w)
            {
                dx[edge[i].v][in.sw+1]=dx[in.id][in.sw]+edge[i].w;
                if(!ex[edge[i].v][in.sw+1])
                {
                    ex[edge[i].v][in.sw+1]=1;
                    temp.id=edge[i].v;
                    temp.sw=in.sw+1;
                    que.push(temp);
                }
            }
        }
    }
    for(int i=1;i<=n;i++)
    {
        if(st==i) continue;
        double min=100000000.0;
        for(int j=1;j<=n;j++)
        {
            if(dx[i][j]!=100000000.0&&dx[i][j]/(double)j<min)
            {
                min=dx[i][j]/(double)j;
            }
        }
        if(min!=100000000.0)
            ans[st][i]=min;
        else
            ans[st][i]=-1;
    }
         
}
 
int main()
{
    //freopen("path.in","r",stdin);
    //freopen("path.out","w",stdout);
    memset(headlist,-1,sizeof(headlist));
    memset(ans,127,sizeof(ans));
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d%d",&a,&b,&t);
        if(map[a][b]==0||t<map[a][b])
        {
            map[a][b]=t;
            edge[i].v=b;
            edge[i].nx=headlist[a];
            edge[i].w=t;
            headlist[a]=i;
        }
 
    }
    for(int i=1;i<=n;i++)
    {
        st=i;
        spfa();
    }
    scanf("%d",&q);
    for(int i=1;i<=q;i++)
    {
        scanf("%d%d",&st,&en);
        if(ans[st][en]==-1)
            printf("OMG!\n");
        else
            printf("%.3lf\n",(double)((int)(ans[st][en]*1000+0.5))/1000);
    }
    return 0;
}