Cod sursa(job #2416914)

Utilizator avtobusAvtobus avtobus Data 28 aprilie 2019 16:02:57
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.81 kb
// Breadth First Search - cu Queue pentru a procesa vecinii
#include <stdio.h>
#include <bits/stdc++.h>

#define rep(i, n) for(int i = 0; i < n; i++)
#define REP(i,a,b) for(int i = a; i < b; i++)

using namespace std;
typedef pair<int, int> pii;
const int INF = 0x3f3f3f3f;
const int Nmax = 100555;

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

int N, M, S, d[Nmax];
vector<int> G[Nmax];

int main(void) {

  fin >> N >> M >> S;
  --S;
  rep(i, N) { d[i] = -1; }
  int a, b;
  rep(i, M) {
    fin >> a >> b;
    --a, --b;
    G[a].push_back(b);
  }

  queue<int> Q;
  d[S] = 0; Q.push(S);
  while(!Q.empty()) {
    int X = Q.front(); Q.pop();
    for(int Y: G[X]) {
      if (d[Y] == -1) {
        d[Y] = d[X] + 1;
        Q.push(Y);
      }
    }
  }

  rep(i, N) { fout << d[i] << ' '; }
  fout << '\n';

  return 0;
}