【HDU3371】Connect the Cities（MST基础题）

注意输入的数据分别是做什么的就好。还有，以下代码用C++交可以过，而且是500+ms，但是用g++就会TLE，很奇怪。

 

 1 #include <iostream>

 2 #include <cstring>

 3 #include <cstdio>

 4 #include <cstdlib>

 5 #include <cmath>

 6 #include <cctype>

 7 #include <algorithm>

 8 #include <numeric>

 9 #include <limits.h>

10 

11 #define typec int

12 using namespace std;

13 

14 const typec inf = 0xffff;

15 const int V = 505;

16 int vis[V]; typec lowc[V];

17 int Map[V][V];

18 

19 typec prim (typec cost[][V], int n) {

20     int i, j, p;

21     typec minc, res = 0;

22     memset(vis, 0, sizeof(vis));

23     vis[0] = 1;

24     for (i = 1; i < n; ++ i) lowc[i] = cost[0][i];

25     for (i = 1; i < n; ++ i) {

26         minc = inf;

27         p = -1;

28         for (j = 0; j < n; ++ j) {

29             if (0 == vis[j] && minc > lowc[j]) {

30                 minc = lowc[j];

31                 p = j;

32             }

33         }

34         if (inf == minc) return -1;

35         res += minc;

36         vis[p] = 1;

37         for (j = 0; j < n; ++ j) {

38             if (0 == vis[j] && lowc[j] > cost[p][j]) {

39                 lowc[j] = cost[p][j];

40             }

41         }

42     }

43     return res;

44 }

45 

46 

47 int main () {

48     int n, road_n, union_n, T;

49     scanf("%d", &T);

50     while (T--) {

51         scanf("%d%d%d", &n, &road_n, &union_n);

52         //cout << "road_n : "  << road_n << endl;

53         for (int i = 0; i < V; ++ i) {

54             for (int j = 0; j < V; ++ j) {

55                 if (i == j) Map[i][j] = 0;

56                 else Map[i][j] = inf;

57             }

58         }

59 

60         for (int i = 0; i < road_n; ++ i) {

61             int x, y, w;

62             scanf("%d%d%d", &x, &y, &w);

63             Map[x - 1][y - 1] = Map[y - 1][x - 1] = min(Map[x - 1][y - 1], w);

64 

65         }

66         /*

67         for (int i = 0 ; i < n; ++ i) {

68             for (int j = 0; j < n; ++ j) {

69                 cout << Map[i][j] << "\t";

70             }

71             cout << endl;

72         }

73         */

74         for (int i = 0; i < union_n; ++ i) {

75             int xx, xx_n, last;

76             scanf("%d", &xx_n);

77             for (int j = 0; j < xx_n; ++ j) {

78                 scanf("%d", &xx);

79                 if (!j) {

80                     last = xx;

81                     continue;

82                 } else {

83                     Map[xx - 1][last - 1] = Map[last - 1][xx - 1] = 0;

84                     last = xx;

85                 }

86             }

87         }

88 

89         printf("%d\n", prim(Map, n));

90     }

91     return 0;

92 }