hdu1301 Jungle Roads （Prim）

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1301

 

 

依旧Prim............不多说了

 1 #include<iostream>

 2 #include<cstdio>

 3 #include<algorithm>

 4 

 5 using namespace std;

 6 

 7 #define MAX 'Z'+5

 8 #define inf 99999999

 9 

10 int map[MAX][MAX],node[MAX],vis[MAX],n,path;

11 

12 void Prim()

13 {

14     int ans='A';

15     node[ans]=0;

16     vis[ans]=1;

17     for(int k='A';k<('A'+n);k++)

18     {

19         //cout<<k<<" "<<n<<endl;

20         int minn=inf;

21         for(int i='A';i<('A'+n);i++)

22         if(!vis[i]&&minn>node[i])

23         {

24             minn=node[i];

25             ans=i;

26         }

27         //printf("%c %d\n",ans,minn);

28         vis[ans]=1;

29         path+=node[ans];

30         //cout<<"      "<<path<<endl;

31 

32         for(int i='A';i<('A'+n);i++)

33         if(!vis[i]&&node[i]>map[ans][i])

34         node[i]=map[ans][i];

35     }

36 }

37 

38 int main()

39 {

40     while(cin>>n&&n)

41     {

42         for(int i='A';i<='Z';i++)

43         {

44             node[i]=inf;

45             vis[i]=0;

46             for(int j='A';j<='Z';j++)

47             map[i][j]=inf;

48         }

49         int N=n-1;

50         char a,b;

51         int t,dist;

52         while(N--)

53         {

54             cin>>a>>t;

55             while(t--)

56             {

57                 cin>>b>>dist;

58                 if(map[a][b]>dist)

59                 map[a][b]=map[b][a]=dist;

60             }

61         }

62         path=0;

63         Prim();

64         cout<<path<<endl;

65     }

66     return 0;

67 }