Cod sursa(job #1817289)

Utilizator edi_laitinLaitin Eduard edi_laitin Data 27 noiembrie 2016 16:23:13
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.96 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
#define Nmax 100005
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
int N,M,sol[Nmax],use[Nmax],S;
vector <int> G[Nmax];
queue <int> Q;
void read()
{
    fin>>N>>M>>S;
    for(int i=1;i<=M;i++)
    {
        int x,y;
        fin>>x>>y;
        G[x].push_back(y);
    }
}
void BFS()
{
    Q.push(S);
    use[S]=1;
    sol[S]=0;
    while(!Q.empty())
    {
        int nod=Q.front();
        Q.pop();
        for(int i=0;i<G[nod].size();i++)
        {
            int Vecin=G[nod][i];
            if(!use[Vecin])
            {
                use[Vecin]=1;
                sol[Vecin]=sol[nod]+1;
                Q.push(Vecin);
            }
        }
    }
    for(int i=1;i<=N;i++)
    {
        if(use[i])
            fout<<sol[i]<<" ";
        else
            fout<<"-1 ";
    }
}
int main()
{
    read();
    BFS();
    return 0;
}