Cod sursa(job #2139863)

Utilizator JiyuuNoTsubasaMaria Guran JiyuuNoTsubasa Data 22 februarie 2018 20:38:11
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.83 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream in("bfs.in");
ofstream out("bfs.out");

vector<int> V[100100];
queue<int> Q;
int n,m,s,x,y,k,a[100100],b[100100];
int viz[100100];

void bfs(int p)
{
    Q.push(p);
    while (!Q.empty())
    {
        int t = Q.front();
        Q.pop();
        for (int i=0; i<V[t].size(); i++)
        {
            if (!viz[V[t][i]] && V[t][i]!= p) Q.push(V[t][i]), viz[V[t][i]] = viz[t] + 1;
        }
    }
}

int main()
{

    in >> n >> m >> s;

    for (int i = 1; i<=m; i++)
    {
        in >> x >> y;
        V[x].push_back(y);
    }

    bfs(s);

    for (int i = 1; i<=n; i++)
    {
        if (i == s) out << "0 ";
        else if (viz[i] == 0) out << "-1 ";
        else out << viz[i] << " ";
    }

    return 0;
}