hdu2112(HDU Today 简单最短路)

#include<stdio.h>  
#include<iostream>  
#include<map>  
#include<queue>  

using namespace std;  

#define INF 99999999  

int Map[155][155],n,node[155];  

void init()  
{  
    for(int i=0;i<=150;i++)  
    for(int j=i;j<=150;j++)  
    Map[i][j]=Map[j][i]=node[i]=INF;  
}  

void spfa(int star)  
{  
    int inQ[155]={0};  
    queue<int>Q;  
    inQ[star]=1; Q.push(star);  
    node[star]=0;  
    while(!Q.empty())  
    {  
        star=Q.front(); Q.pop();  
        inQ[star]=0;  
        for(int i=1;i<=n;i++)  
        if(Map[star][i]+node[star]<node[i])  
        {  
            node[i]=Map[star][i]+node[star];  
            if(!inQ[i])  
            Q.push(i),inQ[i]=1;  
        }  
    }  
}  

int main()  
{  
    int star,end,m,a,b,p;  
    char aa[35],bb[35];  
    map<string,int>loc;  
    while(scanf("%d",&m)>0&&m!=-1)  
    {  
        init(); n=1; loc.clear();  
        scanf("%s%s",aa,bb);  
        loc[aa]=n; star=n;  
        if(!loc[bb]){n++;loc[bb]=n;}  
         end=loc[bb];  
        while(m--)  
        {  
            scanf("%s%s%d",aa,bb,&p);  
            if(!loc[aa]){n++;loc[aa]=n;}a=loc[aa];  
            if(!loc[bb]){n++;loc[bb]=n;}b=loc[bb];  
            if(Map[a][b]>p)  
            Map[a][b]=Map[b][a]=p;  
        }  
        if(star==end)  
        {  
            printf("0\n");continue;  
        }  
        spfa(star);  
        if(node[end]==INF) node[end]=-1;  
        printf("%d\n",node[end]);  
    }  
}