hdu 1875 畅通工程再续

#include <iostream>
#include <algorithm>
#include <iomanip>
#include <cmath>
using namespace std;
int n,p[105]; 
struct point
{
    double x,y,d;
	 
}e[15005],zb[105];
int cmp(point a1,point b1)
{
    return a1.d<b1.d;
}
void init()
{
    for(int i=1;i<=n;i++)
     p[i]=i;
}
int find(int x)
{
    if(x==p[x]) return x;
    else return p[x]=find(p[x]);
}

void jie(int x,int y)
{
    int ta=find(x),tb=find(y);
    if(ta!=tb) p[ta]=tb;
}


double clus(int m)
{
    int x,y,i,c; double ans;
    init();
    for(ans=c=i=0;i<m;i++)
    {
        x=e[i].x;y=e[i].y;
        if(find(x)!=find(y))
        {   ans+=e[i].d;
             c++;
            jie(x,y);
        }
        if(c==n-1) return ans;
    }
    return -1;
}

int main(void)
{
   int t,i,j,k;double d;
   cin>>t;
   while(t--)
   {
   	  cin>>n;
   	  for(i=1;i<=n;i++)
   	   cin>>zb[i].x>>zb[i].y;
   	   if(n==1) cout<<0<<endl;
      for(k=0,i=1;i<=n;i++)
      for(j=i+1;j<=n;j++)
       { d=sqrt((zb[i].x-zb[j].x)*(zb[i].x-zb[j].x)+(zb[i].y-zb[j].y)*(zb[i].y-zb[j].y));
         if(d<10||d>1000)  continue;
       	 e[k].x=i; e[k].y=j; e[k++].d=d;
       }
       if(k<n-1) {cout<<"oh!"<<endl;continue;}
       sort(e,e+k,cmp);
	   d=clus(k);
       if(d==-1) cout<<"oh!"<<endl;
       else cout<<fixed<<setprecision(1)<<d*100<<endl;
   }  
}