*tram<pku 1847>

 //看懂题目之后发现很水，最短路，数据小,直接flyod.
Source Code

Problem: 1847        User: eth1
Memory: 292K        Time: 32MS
Language: C++        Result: Accepted
Source Code
#include <iostream>
#include <cstring>
#include <algorithm>
 using namespace std;
#define maxx 1000000
int map[105][105];
int main()
{
    int a,b,c,n,m;
    cin>>a>>b>>c;
    //memset(map,-1,sizeof(map));
    for(int i=1;i<=a;i++)
    for(int j=1;j<=a;j++)
    map[i][j] = maxx;
    for(int i=1;i<=a;i++)
    {
        cin>>n;
        for(int j=0;j<n;j++)
        {
            cin>>m;
            if(j==0) map[i][m]=0;
            else map[i][m]=1;
        }
    }
    for(int k=1;k<=a;k++)
    for(int i=1;i<=a;i++)
    for(int j=1;j<=a;j++)
    {
        if(map[i][k]+map[k][j] < map[i][j]) map[i][j] = map[i][k]+map[k][j];
    }
    if(map[b][c] == maxx) cout<<-1<<endl;
    else cout<<map[b][c]<<endl;
    return 0;
}