Cod sursa(job #2365640)

Utilizator stefanst77Luca Stefan Ioan stefanst77 Data 4 martie 2019 15:27:44
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.98 kb
#include <bits/stdc++.h>
#define nmax 100007

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

int n, m, el;
vector <int> L[nmax];
int viz[nmax];
int drum[nmax];
queue <int > q;

void Citire()
{
    int i, x, y;
    fin >> n >> m >> el;
    for (i = 1; i <= m; i++)
    {
        fin >> x >> y;
        L[x].push_back(y);
    }
}

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

int main()
{
    Citire();
    BFS(el);
    for (int i = 1; i <= n; i++)
    {
        if (i != el && drum[i] == 0)
            drum[i] = -1;
        fout << drum[i] << " ";
    }
    fout << "\n";
    fin.close();
    fout.close();
    return 0;
}