Cod sursa(job #2669155)

Utilizator goblinupufosPopescu Traian goblinupufos Data 6 noiembrie 2020 11:41:36
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.86 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

int n, m, s;

vector<int> mat[100005];
int sir[100005];

void bfs() {
    queue<int> q;
    q.push(s);
    sir[s] = 1;

    while (!q.empty()) {
        int p = q.front();
        for (int i = 0; i < mat[p].size(); ++i) {
            if (sir[mat[p][i]] == 0) {
                q.push(mat[p][i]);
                sir[mat[p][i]] = sir[p] + 1;
            }
        }
        q.pop();
    }

}

int main() {
    fin >> n >> m >> s;

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

    bfs();

    for (int i = 1; i <= n; ++i) {
        if (sir[i] == 0) {
            fout << -1 << " ";
        } else {
            fout << sir[i] - 1 << " ";
        }
    }

    return 0;
}