【HDU1875】畅通工程再续（MST基础题）
更改成实形数即可。第一次敲完直接交，CE了一次。晕。
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 double 11 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 }
