Cod sursa(job #1695417)

Utilizator andreinmAndrei andreinm Data 27 aprilie 2016 01:47:54
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.92 kb
#include <fstream>
#include <queue>
#include <vector>
using namespace std;

const int MAX_N = 100005;

int n, m, root, X, Y;
int res[MAX_N];
vector <int> G[MAX_N];
queue <int> Q;

void BFS(int node)
{
    vector <int> :: iterator it;
    res[node] = 0;
    Q.push(node);

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

        for (it = G[node].begin(); it != G[node].end(); ++it) {
            if (res[*it] == -1) {
                res[*it] = res[node] + 1;
                Q.push(*it);
            }
        }
    }
}

int main()
{
    ifstream cin("bfs.in");
    ofstream cout("bfs.out");

    cin >> n >> m >> root;

    for (int i = 1; i <= m; ++i) {
        cin >> X >> Y;
        G[X].push_back(Y);
    }

    for (int i = 1; i <= n; ++i)
        res[i] = -1;

    BFS(root);

    for (int i = 1; i <= n; ++i)
        cout << res[i] << " ";

    return 0;
}