Cod sursa(job #2872402)

Utilizator marcpopPop Marc Alexandru marcpop Data 16 martie 2022 22:03:47
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.08 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

queue<int> q;

vector<vector<int> > v;
vector<bool> viz;
vector<int> d;

int n, m, s, a, b;

int bfs(int start) {

    q.push(start);
    viz[start] = 1;

    while (!q.empty()) {

        int poz = q.front();
        q.pop();

        for (int i=0; i<v[poz].size(); i++) {

            int vecin = v[poz][i];

            if (!viz[vecin]) {
                q.push(vecin);
                viz[vecin] = 1;
                d[vecin] = d[poz] + 1;
            }

        }

    }


}

int main()
{

    fin>>n>>m>>s;

    v = vector<vector<int> >(n+2);
    viz = vector<bool>(n+2, 0);
    d = vector<int>(n+2, 0);

    for (int i=1; i<=m; i++) {

        fin>>a>>b;

        v[a].push_back(b);

    }

    bfs(s);

    for (int i=1; i<=n; i++) {

        if (!viz[i]) {
            fout<<-1<<" ";
        }
        else {
            fout<<d[i]<<" ";
        }

    }

    return 0;
}