Freckles

#include <stdio.h>
#include <cmath>
#include <queue>
using namespace std;
int N;
double vert[128][128],x[128],y[128];
bool cn[128];
struct pr{
    pr(double f,int s):first(f),second(s){};
    double first;
    int second;
    bool operator<(const pr &o)const{return first>o.first;}
};
inline double dist(double x1,double y1,double x2,double y2){
    double X(x2-x1),Y(y1-y2);
    return sqrt(X*X+Y*Y);
}
double solve(void){
    priority_queue<pr> q;
    q.push(pr(0,0));
    double tot(0);
    while(!q.empty()){
        tot+=q.top().first;
        int act(q.top().second);
        q.pop();
        cn[act]=true;
        for(int i(0);i<N;++i)
            q.push(pr(vert[act][i],i));
        while(!q.empty()&&cn[q.top().second])
            q.pop();
    }
    return tot;
}
int main(void){
    int tt;
    scanf("%d",&tt);
    for(int g(0);tt--;++g){
        if(g)
            printf("\n");
        scanf("%d",&N);
        for(int i(0);i<N;++i){
            cn[i]=false;
            scanf("%lf%lf",&x[i],&y[i]);
            vert[i][i]=0;
        }
        for(int i(0);i<N;++i)
            for(int j(i+1);j<N;++j)
                vert[i][j]=vert[j][i]=dist(x[i],y[i],x[j],y[j]);
        printf("%.2f\n",solve());
    }
    return 0;
}