【HDU1879】继续畅通工程（MST基础题）
真心大水题。。。不多说。
1 #include <iostream> 2 #include <cstring> 3 #include <cstdlib> 4 #include <cstdio> 5 #include <cctype> 6 #include <cmath> 7 #include <algorithm> 8 #include <numeric> 9 10 #define typec int 11 using namespace std; 12 13 const typec inf = 0xffff; 14 const int V = 105; 15 int vis[V]; 16 typec lowc[V], Map[V][V]; 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; 26 p = -1; 27 for (j = 0 ; j < n; ++ j) { 28 if (0 == vis[j] && minc > lowc[j]) { 29 minc = lowc[j]; 30 p = j; 31 } 32 } 33 if (inf == minc) return -1; 34 res += minc; 35 vis[p] = 1; 36 for (j = 0 ; j < n; ++ j) { 37 if (0 == vis[j] && lowc[j] > cost[p][j]) { 38 lowc[j] = cost[p][j]; 39 } 40 } 41 } 42 return res; 43 } 44 45 int main () { 46 int n; 47 while (~scanf("%d", &n)) { 48 if (!n) break; 49 for (int i = 0 ; i < V; ++i) { 50 for (int j = 0; j < V; ++ j) { 51 if (i == j) Map[i][j] = 0; 52 else Map[i][j] = inf; 53 } 54 } 55 56 for (int i = 0 ; i < n * (n - 1) / 2; ++i) { 57 int x, y, w, ok; 58 scanf("%d%d%d%d", &x, &y, &w, &ok); 59 if (!ok) { 60 Map[x - 1][y - 1] = Map[y - 1][x - 1] = min(Map[x][y], w); 61 } else { 62 Map[x - 1][y - 1] = Map[y - 1][x - 1] = 0; 63 } 64 } 65 66 cout << prim(Map, n) << endl; 67 } 68 return 0; 69 }
