Cod sursa(job #3361254)

Utilizator livliviLivia Magureanu livlivi Data 22 iulie 2026 13:38:11
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.02 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

// O(m)
vector<int> bfs(int src, vector<vector<int>>& edges) {
    queue<int> q;
    vector<int> dist(edges.size(), -1);

    q.push(src);
    dist[src] = 0;
    while (!q.empty()) {
        int node = q.front();
        q.pop();

        for (int i = 0; i < edges[node].size(); i++) {
            int vecin = edges[node][i];
            if (dist[vecin] == -1) {
                dist[vecin] = dist[node] + 1;
                q.push(vecin);
            }
        }
    }

    return dist;
}

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

    int n, m; cin >> n >> m;
    int s; cin >> s;
    vector<vector<int>> edges(n);
    for (int i = 0; i < m; i++) {
        int a, b; cin >> a >> b;
        a--; b--;
        edges[a].push_back(b);
//        edges[b].push_back(a);
    }

    vector<int> dist = bfs(s, edges);

    for (int i = 0; i < n; i++) {
        cout << dist[i] << " ";
    }
    cout << "\n";

    return 0;
}