Cod sursa(job #2839742)

Utilizator AdrianDiaconitaAdrian Diaconita AdrianDiaconita Data 26 ianuarie 2022 15:03:47
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.95 kb
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

const int NMAX = 100001;
int n, m, s;
vector < int > ad[NMAX];
queue < int > Q;
int vis[NMAX];

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

void bfs(int nod)
{
    Q.push(nod);
    vis[nod] = 1;
    while (!Q.empty())
    {
        int v = Q.front();
        Q.pop();

        for (int i = 0; i < ad[v].size(); ++i)
        {
            int w = ad[v][i];
            if (vis[w] == 0)
            {
                Q.push(w);
                vis[w] = vis[v] + 1;
            }
        }
    }
}

int main()
{
    read();
    bfs(s);
    for (int i = 1; i <= n; ++i)
    {
        if (vis[i] == 0) fout << -1 << ' ';
        else fout << vis [i] - 1 << ' ';
    }
    return 0;
}