Cod sursa(job #3316947)

Utilizator stefanpopaPopa Stefan Gabriel stefanpopa Data 21 octombrie 2025 14:57:30
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.03 kb
#include <iostream>
#include <vector>
#include <queue>
#include <fstream>
using namespace std;

const int NMAX = 100005;
const int INF = 1000000000;
int N, M, S;
vector<int> graf[NMAX];
int D[NMAX];

void BFS(int S) {
    queue<int> Q;
    for (int i = 1; i <= N; i++)
        D[i] = INF;
    D[S] = 0;
    Q.push(S);
    while (!Q.empty()) {
        int nod = Q.front();
        Q.pop();

        for (int vecin : graf[nod]) {
            if (D[vecin] > D[nod] + 1) {
                D[vecin] = D[nod] + 1;
                Q.push(vecin);
            }
        }
    }
}

int main() {
    ifstream fin("bfs.in");
    ofstream fout("bfs.out");
    fin >> N >> M >> S;
    for (int i = 0; i < M; i++) {
        int x, y;
        fin >> x >> y;
        graf[x].push_back(y); 
    }
    BFS(S);

    for (int i = 1; i <= N; i++) {
        if (D[i] == INF)
            fout << -1 << " ";
        else
            fout << D[i] << " ";
    }
    fout << "\n";
    fin.close();
    fout.close();
    return 0;
}