Cod sursa(job #2193818)

Utilizator Cyg_PEduardPetcu Eduard Cyg_PEduard Data 11 aprilie 2018 16:38:54
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.83 kb
#include <fstream>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;
const int NMAX=1000000;
vector<int>G[NMAX+5],d;
vector<bool>viz;
queue<int>q;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
int n;
void bfs(int u)
{
  int v,j;
  viz.assign(n+1,0);
  d.assign(n+1,0);
  q.push(u);
  viz[u]=1;
  while(!q.empty())
  {
    u=q.front();
    q.pop();
    for(j=0;j<G[u].size();j++)
    {
      v=G[u][j];
      if(viz[v]==0)
      {
        viz[v]=1;
        d[v]=d[u]+1;
        q.push(v);
      }
    }
  }
}
int main()
{
    int m,s,u,v,i;
    fin>>n>>m>>s;
    for(i=1;i<=m;i++)
    {
      fin>>u>>v;
      G[u].push_back(v);
    }
    bfs(s);
    for(i=1;i<=n;i++)
      if(d[i]==0 && i!=s)
        d[i]=-1;
    for(i=1;i<=n;i++)
      fout<<d[i]<<" ";
    return 0;
}