1 #include <iostream> 2 #include <cstring> 3 #include <cstdio> 4 #include <cstdio> 5 #include <cctype> 6 #include <cmath> 7 #include <algorithm> 8 #include <numeric> 9 10 #define typec double11 using namespace std;12 13 const typec inf = 0xffff;14 const int V = 1005;15 int vis[V];16 typec lowc[V], Map[V][V], point[V][2];17 18 typec prim (typec cost[][V], int n) {19     int i, j, p;20     typec minc, res = 0;21     memset(vis, 0, sizeof(vis));22     vis[0] = 1;23     for (i = 1; i < n; ++ i) lowc[i] = cost[0][i];24     for (i = 1; i < n; ++ i) {25         minc = inf; p = -1;26         for (j = 0; j < n; ++ j ) {27             if (0 == vis[j] && minc > lowc[j]) {28                 minc = lowc[j];29                 p = j;30             }31         }32         if (inf == minc) return -1;33         res += minc;34         vis[p] = 1;35         for (j = 0; j < n; ++ j) {36             if (0 == vis[j] && lowc[j] > cost[p][j]) {37                 lowc[j] = cost[p][j];38             }39         }40     }41     return res;42 }43 44 double cal_dis (double x1, double y1, double x2, double y2) {45     return sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));46 }47 48 int main () {49     int T; scanf("%d", &T);50     while (T --) {51         //vector<pair<double, double> > p;52         int n; scanf("%d", &n);53         for (int i = 0; i < n; ++ i) {54             scanf("%lf%lf", &point[i][0], &point[i][1]);55         }56 57         for (int i = 0 ; i < 105; ++ i) {58             for (int j = 0; j < 105; ++ j) {59                 if (i == j) Map[i][j] = 0;60                 else Map[i][j] = inf;61             }62         }63 64         for (int i = 0; i < n; ++i) {65             for (int j = i + 1; j < n; ++ j) {66                 double w = cal_dis(point[i][0], point[i][1],point[j][0],point[j][1]);67                 if (w >= 10 && w <= 1000)68                     Map[i][j] = Map[j][i] = min(Map[i][j], w);69                 else continue;70                 /*cout << Map[i][j] << endl;71                 cout << Map[j][i] << endl;*/72             }73         }74 75         /*for (int i = 0; i < 2; ++ i) {76             for (int j = 0 ; j < 2; ++ j) {77                 cout << Map[i][j] << " ";78             }79             cout << endl;80         }*/81         double ans = 100 * prim(Map, n);82         if (ans > 0)83             printf("%.1lf\n", ans);84         else {85             printf("oh!\n");86         }87         //cout << prim (Map, n) << endl;88     }89     return 0;90 }