hdoj 1875 畅通工程再续

题目传送门：
http://acm.hdu.edu.cn/showproblem.php?pid=1875

//9403289    2013-10-24 17:00:49    Accepted    1875    62MS    376K    2205 B    C++    空信高手

#include <iostream>

#include <cmath>

#include <iomanip>

using namespace std;

#define typec double

#define V 101

const typec inf=10000000;

int vis[V];

typec lowc[V],cost[V][V];

typedef struct

{

    int x;

    int y;

} POINT;

POINT pnts[V];

/*=================================================*\

 | Prim求MST

 | INIT: cost[][]耗费矩阵(inf为无穷大);

 | CALL: prim(cost, n); 返回-1代表原图不连通;

\*==================================================*/

typec prim(int n)

{

    int i,j,p;

    typec minc,res=0;

    memset(vis,0,sizeof(vis));

    vis[0]=1;

    for(i=1; i<n; i++) lowc[i]=cost[0][i];

    for(i=1; i<n; i++)

    {

        minc=inf;

        p=-1;

        for(j=0; j<n; j++)

        {

            if(0==vis[j]&&minc>lowc[j])

            {

                minc=lowc[j];

                p=j;

            }

        }

        if(inf==minc) return -1;

        res+=minc;

        vis[p]=1;

        for(j=0; j<n; j++)

            if(0==vis[j]&&lowc[j]>cost[p][j])lowc[j]=cost[p][j];

    }

    return res;

}



double calDis(POINT a,POINT b)

{

    return sqrt(double((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y)));

}

void Init()

{

    int i,j;

    for(i=0; i<V; i++)

        for(j=0; j<V; j++)

            cost[i][j]=10000000;

}

int main()

{

   // freopen("input.txt","r",stdin);

    int n,i,j;

    while(cin>>n&&n!=0)

    {

        while(n--)

        {

            int m;

            double Sum=0;

            cin>>m;

            Init();

            //memset(cost,inf,sizeof(cost));



            for(i=0; i<m; i++)

                cin>>pnts[i].x>>pnts[i].y;

            for(i=0; i<m; i++)

                for(j=0; j<m; j++)

                {

                    if(calDis(pnts[i],pnts[j])<=1000.000001&&calDis(pnts[i],pnts[j])>=10.000000)

                        cost[i][j]=calDis(pnts[i],pnts[j]);

                }

//            if(!flag) cout<<setiosflags(ios::fixed)<<setprecision(1)<<prim(m)*100<<endl;

//            else cout<<"oh!"<<endl;

            Sum=prim(m);

            if(Sum<0) cout<<"oh!"<<endl;

            else cout<<setiosflags(ios::fixed)<<setprecision(1)<<Sum*100<<endl;

        }

    }

    return 0;

}