Cod sursa(job #2191917)

Utilizator timar_andreiTimar Andrei timar_andrei Data 4 aprilie 2018 08:59:40
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.9 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

ifstream fin("bfs.in");
ofstream fout("bfs.out");

int N,M,S;
vector <int>G[100004];
int D[100004];
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(int s)
{
    for(int i=1;i<=N;i++)
        D[i] = -1;

    D[s] = 0;
    Q.push(s);

    while(!Q.empty())
    {
        int nod = Q.front();
        Q.pop();

        for(int i=0;i<G[nod].size();i++)
        {
            int vecin = G[nod][i];

            if (D[vecin] == -1)
            {
                D[vecin] = D[nod] + 1;
                Q.push(vecin);
            }
        }
    }
}

int main()
{
    Read();
    BFS(S);

    for(int i=1;i<=N;i++)
        fout<<D[i]<<' ';

    return 0;
}