Cod sursa(job #2788426)

Utilizator Razvan48Capatina Razvan Nicolae Razvan48 Data 25 octombrie 2021 17:48:00
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.21 kb
#include <fstream>
#include <vector>
#include <climits> /// pentru INT_MAX
#include <queue> /// pentru coada

using namespace std;

const int NMAX = 100000;

vector<int> graf[1 + NMAX];

int distMinima[1 + NMAX];

queue<pair<int, int>> q;

int main()
{
  ifstream in("bfs.in");
  ofstream out("bfs.out");

  int n, m, s;
  in >> n >> m >> s;

  for (int j = 1; j <= m; j++)
  {
    int x, y;
    in >> x >> y; /// muchie orientata x->y

    graf[x].push_back(y);
    /// graf[y].push_back(x); /// asta pentru graf neorientat
  }

  for (int i = 1; i <= n; i++)
    distMinima[i] = INT_MAX;

  distMinima[s] = 0;
  q.push(make_pair(s, 0));

  while (!q.empty())
  {
    int nod = q.front().first;
    int distanta = q.front().second;
    q.pop();

    for (int i = 0; i < graf[nod].size(); i++)
    {
      int vecin = graf[nod][i];

      if (distMinima[vecin] > distanta + 1)
      {
        distMinima[vecin] = distanta + 1;

        q.push(make_pair(vecin, distMinima[vecin]));
      }
    }
  }

  for (int i = 1; i <= n; i++)
  {
    if (distMinima[i] != INT_MAX)
      out << distMinima[i] << ' ';
    else
      out << -1 << ' ';
  }
  out << '\n';

  return 0;
}