使用了scanf输入,之前RE,看了discuss之后才发现,行末可能有多个空格,所以要循环getchar()
附代码:

#include<cstdio>
#include<cstring>
#define INF 0x3f3f3f3f
using namespace std;
int n,ans=0;
int Min,tmp;
int matrix[100][100];
int dis[100];
bool vis[100];
void prim()
{

    for(int i = 0; i<n; ++i)
        dis[i] = matrix[0][i];
    vis[0] = 1;
    for(int i = 1; i<n; ++i)
    {
        Min = INF;
        for(int j = 1; j<n; ++j)
        {
            if(!vis[j]&&Min>dis[j])
            {
                Min = dis[j];
                tmp = j;
            }
        }
        vis[tmp] = 1;
        for(int i = 0; i<n; ++i)
        {
            if(!vis[i]&&dis[i]>matrix[tmp][i])
                dis[i] = matrix[tmp][i];
        }
    }
    for(int i = 0; i<n; ++i)
        ans += dis[i];
    printf("%d\n",ans);
}
int main()
{
    char v1,v2,sp;
    int cnt=0,val,c;
    while(scanf("%d",&n),n)
    {
        memset(vis,0,sizeof(vis));
        ans = 0;
        for(int i = 0; i<n; ++i)
        {
            for(int j = 1; j<n; ++j)
            {
                matrix[i][j] = (j==i)?0:INF;
            }
        }
        for(int i = 0; i<n-1; ++i)
        {
            //行末可能有多个空格
            while(1)
            {
                c = getchar();
                if(c>='A'&&c<='Z')
                    break;
            }
            v1 = c;
            scanf("%c%d",&sp,&cnt);
            for(int j = 0; j<cnt; ++j)
            {
                scanf("%c%c%d",&sp,&v2,&val);
                matrix[v1-'A'][v2-'A'] = matrix[v2-'A'][v1-'A'] = val;
            }
        }
        prim();
    }
    return 0;
}