Cod sursa(job #2382434)

Utilizator vcerneaCernea Victor vcernea Data 18 martie 2019 12:14:44
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.76 kb

#include <bits/stdc++.h>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");

int n, m, l, start;
vector<int> a[100005];
int g[100005], s[100005], cost[100005];

void bfs(int x) {
  int i, j;
  l = 1;
  s[l] = x;
  cost[x] = 0;
  for (i = 1; i <= l; i++)
    for (j = 0; j < g[s[i]]; j++)
      if (cost[a[s[i]][j]] == -1) {
        s[++l] = a[s[i]][j];
        cost[s[l]] = cost[s[i]] + 1;
      }
}

int main() {
  int i, x, y;
  fin >> n >> m >> start;
  fill(cost + 1, cost + n + 1, -1);
  for (i = 1; i <= m; i++) {
    fin >> x >> y;
    a[x].push_back(y);
  }

  for (i = 1; i <= n; i++)
    g[i] = a[i].size();
  bfs(start);
  for (i = 1; i <= n; i++)
    fout << cost[i] << " ";
  fout << '\n';
  return 0;
}