Cod sursa(job #3155997)

Utilizator mafiStefan Maftei mafi Data 10 octombrie 2023 13:24:11
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.89 kb
// BFS

#include <fstream>
#include <vector>
#include <queue>
using namespace std;

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

const int nmax = 1e5;
int d[nmax + 1];
bool viz[nmax + 1];
int n, m, s;

queue <int> q;
vector <int> g[nmax + 1];

void Citire() {

	fin >> n >> m >> s;
	for (int i = 1; i <= m; i++) {
		int x, y;
		fin >> x >> y;
		g[x].push_back(y);
	}
}

void BFS(int x) {
	q.push(x);
	viz[x] = 1;
	d[x] = 0;
	while (!q.empty()) {
		int nod = q.front();
		q.pop();
		for (auto vecin : g[nod]) {
			if (!viz[vecin]) {
				viz[vecin] = 1;
				d[vecin] = d[nod] + 1;
				q.push(vecin);
			}
		}
	}

}

void Afisare() {
    for (int i = 1; i <= n; i++) {
        if (d[i] == 0 && i != s)
            fout << -1 << " ";
        else
            fout << d[i] << " ";
    }
}

int main()
{
	Citire();
	BFS(s);
    Afisare();
	return 0;
}