hdu 2066 最短路

建立一个超级源点0和超级汇点n，求0到n的最短路就行了。

dijstra：

 1 #include <algorithm>

 2 #include <iostream>

 3 #include <cstring>

 4 #include <cstdio>

 5 using namespace std;

 6 

 7 const int INF = 9999999;

 8 const int N = 2001;

 9 const int M = 100000;

10 int head[N];

11 int dist[N];

12 bool visit[N];

13 int n, e;

14 

15 struct Edge

16 {

17     int v, next, w;

18 } edge[M];

19 

20 void addEdge( int u, int v, int w )

21 {

22     edge[e].v = v;

23     edge[e].w = w;

24     edge[e].next = head[u];

25     head[u] = e++;

26 }

27 

28 void dij( int s )

29 {

30     memset( visit, false, sizeof(visit) );

31     for ( int i = 0; i <= n; i++ )

32     {

33         dist[i] = INF;

34     }

35     dist[s] = 0;

36     for ( int i = 0; i <= n; i++ )

37     {

38         int minn = INF, u;

39         for ( int j = 0; j <= n; j++ )

40         {

41             if ( !visit[j] && dist[j] < minn )

42             {

43                 minn = dist[j];

44                 u = j;

45             }

46         }

47         visit[u] = true;

48         for ( int j = head[u]; j != -1; j = edge[j].next )

49         {

50             int v = edge[j].v, w = edge[j].w;

51             if ( !visit[v] && dist[u] + w < dist[v] )

52             {

53                 dist[v] = dist[u] + w;

54             }

55         }

56     }

57 }

58 

59 int main ()

60 {

61     int t, s, d;

62     while ( scanf("%d%d%d", &t, &s, &d) != EOF )

63     {

64         e = n = 0;

65         memset( head, -1, sizeof(head) );

66         while ( t-- )

67         {

68             int u, v, w;

69             scanf("%d%d%d", &u, &v, &w);

70             addEdge( u, v, w );

71             addEdge( v, u, w );

72             if ( u > n ) n = u;

73             if ( v > n ) n = v;

74         }

75         n++;

76         for ( int i = 0; i < s; i++ )

77         {

78             int tmp;

79             scanf("%d", &tmp);

80             addEdge( 0, tmp, 0 );

81         }

82         for ( int i = 0; i < d; i++ )

83         {

84             int tmp;

85             scanf("%d", &tmp);

86             addEdge( tmp, n, 0 );

87         }

88         dij(0);

89         printf("%d\n", dist[n]);

90     }

91     return 0;

92 } 

spfa：

 1 #include <algorithm>

 2 #include <iostream>

 3 #include <cstring>

 4 #include <cstdio>

 5 using namespace std;

 6 

 7 const int INF = 9999999;

 8 const int N = 2001;

 9 const int M = 100000;

10 int head[N];

11 int dist[N];

12 bool visit[N];

13 int n, e;

14 

15 struct Edge

16 {

17     int v, next, w;

18 } edge[M];

19 

20 void addEdge( int u, int v, int w )

21 {

22     edge[e].v = v;

23     edge[e].w = w;

24     edge[e].next = head[u];

25     head[u] = e++;

26 }

27 

28 void spfa( int s )

29 {

30     for ( int i = 0; i <= n; i++ )

31     {

32         dist[i] = INF;

33         visit[i] = false;

34     }

35     dist[s] = 0;

36     visit[s] = true;

37     int q[N], top = 0;

38     q[top] = s;

39     top = ( top + 1 ) % ( n + 1 );

40     for ( int i = 0; i != top; i = ( i + 1 ) % ( n + 1 ) )

41     {

42         int u = q[i];

43         visit[u] = false;

44         for ( int j = head[u]; j != -1; j = edge[j].next )

45         {

46             int v = edge[j].v, w = edge[j].w;

47             if ( dist[v] > dist[u] + w )

48             {

49                 dist[v] = dist[u] + w;

50                 if ( !visit[v] )

51                 {

52                     q[top] = v;

53                     top = ( top + 1 ) % ( n + 1 );

54                     visit[v] = true;

55                 }

56             }

57         }

58     }

59 }

60 

61 int main ()

62 {

63     int t, s, d;

64     while ( scanf("%d%d%d", &t, &s, &d) != EOF )

65     {

66         e = n = 0;

67         memset( head, -1, sizeof(head) );

68         while ( t-- )

69         {

70             int u, v, w;

71             scanf("%d%d%d", &u, &v, &w);

72             addEdge( u, v, w );

73             addEdge( v, u, w );

74             if ( u > n ) n = u;

75             if ( v > n ) n = v;

76         }

77         n++;

78         for ( int i = 0; i < s; i++ )

79         {

80             int tmp;

81             scanf("%d", &tmp);

82             addEdge( 0, tmp, 0 );

83         }

84         for ( int i = 0; i < d; i++ )

85         {

86             int tmp;

87             scanf("%d", &tmp);

88             addEdge( tmp, n, 0 );

89         }

90         spfa(0);

91         printf("%d\n", dist[n]);

92     }

93     return 0;

94 }