Cod sursa(job #1428188)

Utilizator greenadexIulia Harasim greenadex Data 3 mai 2015 20:54:36
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.84 kb
#include <fstream>
#include <vector>
#include <deque>

using namespace std;

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

deque<pair<int, int>> q;
vector<int> v[100001];
int vizit[100001];
int n, m, s;

int main()
{
    fin >> n >> m >> s;
    for (int a, b; m; m--){
        fin >> a >> b;
        v[a].push_back(b);
    }
    q.push_back(make_pair(s, 0));
    while(!q.empty()){
        int x = q.front().first;
        for (auto it: v[x])
            if (!vizit[it]){
                int len = q.front().second + 1;
                q.push_back(make_pair(it, len));
                vizit[it] = len;
            }
        q.pop_front();
    }
    vizit[s] = 0;
    for (int i = 1; i <= n; i++)
        if (!vizit[i] && i != s)
            fout << -1 << ' ';
        else fout << vizit[i] << ' ';
    return 0;
}