Cod sursa(job #2032952)

Utilizator BourucLiviuBouruc Petru Liviu BourucLiviu Data 5 octombrie 2017 21:51:02
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.92 kb
#include <fstream>
#include <vector>
#include <queue>

#define N 100005

using namespace std;

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

vector <int> v[N];
queue <int> q;
int dist[N];
bool f[N];

void BFS(int x)
{
    vector <int>::iterator it;

    f[x] = 1;
    dist[x] = 0;
    q.push(x);
    while(!q.empty())
    {
        for(it = v[q.front()].begin(); it != v[q.front()].end(); ++it)
            if(!f[*it])
            {
                f[*it] = 1;
                dist[*it] = dist[q.front()] + 1;
                q.push(*it);
            }
        q.pop();
    }
}

int main()
{
    int n, m, s, x, y;
    fin >> n >> m >> s;
    while(m--)
    {
        fin >> x >> y;
        v[x].push_back(y);
    }
    fin.close();

    for(int i = 1; i <= n; ++i) dist[i] = -1;
    BFS(s);

    for(int i = 1; i <= n; ++i) fout << dist[i] << " ";
    fout.close();
    return 0;
}