Cod sursa(job #3295154)

Utilizator Cristina_Micu0731Micu Alexandra Cristina Cristina_Micu0731 Data 2 mai 2025 19:29:41
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.04 kb
#include <fstream>
#include <vector>
#include <queue>
#include <limits>
using namespace std;

const int INF = numeric_limits<int>::max();

int n, m, s;
vector<vector<int>> adj;

// Complexitate: O(n + m)
vector<int> bfs(int source) {
    vector<int> d(n + 1, INF);
    queue<int> q;

    q.push(source);
    d[source] = 0;

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

        for (int neigh : adj[node]) {
            if (d[node] + 1 < d[neigh]) {
                d[neigh] = d[node] + 1;
                q.push(neigh);
            }
        }
    }

    for (int i = 1; i <= n; ++i) {
        if (d[i] == INF) {
            d[i] = -1;
        }
    }

    return d;
}

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

    fin >> n >> m >> s;
    adj.resize(n + 1);

    for (int i = 0; i < m; ++i) {
        int x, y;
        fin >> x >> y;
        adj[x].push_back(y);
    }

    vector<int> dist = bfs(s);

    for (int i = 1; i <= n; ++i) {
        fout << dist[i] << " ";
    }
    fout << "\n";

    return 0;
}