hdoj1875

//prim算法
#include<iostream>
#include<stdio.h>
#include<string.h>
#include<math.h>
using namespace std;
int T, C, heap_size;
double map[100][100];
double V[100][100];
pair < double, int >heap[100];    //first保存距离,second保存岛的编号
void up(int i)
{
    while (i > 1 && heap[i].first < heap[i / 2].first) {
    swap(heap[i], heap[i / 2]);
    i /= 2;
    }
}

void down(int i)
{
    int j = i * 2;
    while (j <= heap_size) {
    if (j < heap_size && heap[j].first > heap[j + 1].first)
        j++;
    if (heap[i].first <= heap[j].first)
        break;
    swap(heap[i], heap[j]);
    i = j;
    j *= 2;
    }
}

int main()
{
    scanf("%d", &T);
    while (T--) {
    scanf("%d", &C);
    double sum = 0;
    heap_size = C - 1;
    for (int i = 0; i < C; ++i) {
        scanf("%lf%lf", &V[i][0], &V[i][1]);
        for (int j = 0; j < i; ++j) {
        double distmp =
            sqrt((V[i][0] - V[j][0]) * (V[i][0] - V[j][0]) +
             (V[i][1] - V[j][1]) * (V[i][1] - V[j][1]));
        if (distmp >= 10 && distmp <= 1000)
            map[i][j] = map[j][i] = distmp;
        else
            map[i][j] = map[j][i] = 1000000;
        }
    }
//init heap
    for (int i = 1; i < C; ++i) {
        heap[i].first = map[0][i];
        heap[i].second = i;
    }
    for (int i = C / 2; i; --i)
        down(i);
    for (int i = 1; i < C; ++i) {
        int u = heap[1].second;
        sum += heap[1].first;
        heap[1] = heap[heap_size];
        heap_size--;
        down(1);
        for (int j = 1; j <= heap_size; ++j) {
        if (heap[j].first > map[u][heap[j].second]) {
            heap[j].first = map[u][heap[j].second];
            up(j);
        }
        }
    }
    if (sum > (C - 1) * 1000)
        printf("oh!\n");
    else
        printf("%.1lf\n", sum * 100);
    }
}