Cod sursa(job #3367098)

Utilizator fmi-studentnu sunt de acord fmi-student Data 6 octombrie 2026 10:40:40
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.25 kb
#include <bits/stdc++.h>
using namespace std;

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

int bfs(vector<vector<int>>& adj, int start, int target) {
    if (start == target) return 0;

    int nodes = adj.size();
    vector<bool> visited(nodes, false);

    queue<pair<int, int>> q;

    visited[start] = true;
    q.push({start, 0});

    while (!q.empty()) {
        auto curr = q.front();
        q.pop();

        for (int x : adj[curr.first]) {
            if (x == target) {
                return curr.second + 1;
            }
            if (!visited[x]) {
                visited[x] = true;
                q.push({x, curr.second + 1});
            }
        }
    }

    return -1;
}

int main() {
    int n, m, s;
    fin >> n >> m >> s;
    vector<vector<int>> adj(n+1);

    int x, y;
    while (m--) {
        fin >> x >> y;
        adj[x].push_back(y);
    }

    vector<int> d(n+1, -1);
    queue<int> q;

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

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

        for (int x : adj[nod]) {
            if (d[x] == -1) {
                d[x] = d[nod] + 1;
                q.push(x);
            }
        }
    }

    for (int i = 1; i <= n; ++i) {
        fout << d[i] << ' ';
    }

    return 0;
}