hdu1301 Jungle Roads （Prim）

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

 

 

依旧Prim............不多说了

#include<iostream>
#include<cstdio>
#include<algorithm>

using namespace std;

#define MAX 'Z'+5
#define inf 99999999

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

void Prim()
{
    int ans='A';
    node[ans]=0;
    vis[ans]=1;
    for(int k='A';k<('A'+n);k++)
    {
        //cout<<k<<" "<<n<<endl;
        int minn=inf;
        for(int i='A';i<('A'+n);i++)
        if(!vis[i]&&minn>node[i])
        {
            minn=node[i];
            ans=i;
        }
        //printf("%c %d\n",ans,minn);
        vis[ans]=1;
        path+=node[ans];
        //cout<<"      "<<path<<endl;

        for(int i='A';i<('A'+n);i++)
        if(!vis[i]&&node[i]>map[ans][i])
        node[i]=map[ans][i];
    }
}

int main()
{
    while(cin>>n&&n)
    {
        for(int i='A';i<='Z';i++)
        {
            node[i]=inf;
            vis[i]=0;
            for(int j='A';j<='Z';j++)
            map[i][j]=inf;
        }
        int N=n-1;
        char a,b;
        int t,dist;
        while(N--)
        {
            cin>>a>>t;
            while(t--)
            {
                cin>>b>>dist;
                if(map[a][b]>dist)
                map[a][b]=map[b][a]=dist;
            }
        }
        path=0;
        Prim();
        cout<<path<<endl;
    }
    return 0;
}