Isenbaev's Number

///https://trello.com/c/0Qqn6lbD/21-timus-1837-isenbaevs-number
///http://acm.timus.ru/problem.aspx?space=1&num=1837
#include <iostream>
#include <vector>
#include <map>
#include <queue>
#define INF (1<<29)
using namespace std;

struct graf {
    vector< vector<long> > ady;
    map<string,long> mapa;
    vector<long> dist;
    long n, m;

    long dar_id (string pal)
    {
        if (mapa[pal]==0)
            mapa[pal]=mapa.size();

        return mapa[pal];
    }

    void BFS (long inicial)
    {
        queue<long> cola;

        cola.push(inicial);
        dist[inicial]=0;

        while( cola.size() )
        {
            long nodo = cola.front();
            cola.pop();

            for(long i=0; i<ady[nodo].size(); i++)
            {
                long vecino = ady[nodo][i];
                if ( dist[nodo]+1 < dist[vecino] )
                {
                    dist[vecino] = dist[nodo]+1;
                    cola.push(vecino);
                }
            }
        }

        for(auto i:mapa)
        {
            cout<<i.first<<" ";
            if(dist[i.second]!=INF)
                cout<<dist[i.second]<<endl;
            else cout<<"undefined"<<endl;
        }
    }

    void leer ()
    {
        cin>>m;

        ady.resize(301);

        string A, B, C;
        for(long i=0; i<m; i++)
        {
            cin>>A>>B>>C;
            long a = dar_id(A);
            long b = dar_id(B);
            long c = dar_id(C);

            ady[a].push_back(b);
            ady[a].push_back(c);
            ady[b].push_back(a);
            ady[b].push_back(c);
            ady[c].push_back(a);
            ady[c].push_back(b);
        }

        n = mapa.size();
        ady.resize(n+1);
        dist = vector<long> (n+1,INF);

        BFS( mapa["Isenbaev"] );
    }
};

int main ()
{
    graf g;
    g.leer();

    return 0;
}