Cod sursa(job #2870454)

Utilizator LukyenDracea Lucian Lukyen Data 12 martie 2022 12:50:11
Problema BFS - Parcurgere in latime Scor 80
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.01 kb
#include <bits/stdc++.h>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");

int main()
{
    int nr_muchii, nr_noduri, start;

    unordered_map<int, int> visit;

    fin >> nr_noduri >> nr_muchii >> start;
    vector<vector<int>> graf(nr_noduri + 1);

    for (int i = 1; i <= nr_muchii; i++)
    {
        int n1, n2;
        fin >> n1 >> n2;
        graf[n1].push_back(n2);
    }

    queue<int>coada;
    coada.push(start);
    visit[start] = 1;
    while (!coada.empty())
    {
        int nod = coada.front();
        coada.pop();
        for (int next:graf[nod])
            if (visit[next]==0)
            {
                visit[next] = visit[nod] + 1;
                coada.push(next);
            }
    }
    visit[start] = 0;
    for (int i = 1; i <= nr_noduri; i++)
    {
        if (visit[i] == 0 && i != start)
            visit[i] = -1;
        else if (i != start)
            visit[i]--;
        fout << visit[i] << " ";
    }

    return 0;
}