Cod sursa(job #1775740)

Utilizator LizaSzabo Liza Liza Data 10 octombrie 2016 17:52:35
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.97 kb
#include <fstream>
#include <vector>
#include <queue>
#include <cstring>

using namespace std;

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

const int NMax = 100005;
int N,M,S;
vector <int> G[100005];
queue <int> Q;
int D[100005],C[NMax];

void Read()
{
  fin>>N>>M>>S;
  for(int i = 1; i <= M; ++i)
    {
      int x,y;
      fin>>x>>y;
      G[x].push_back(y);
    }
}

void BFS(int Start)
{
  memset(D,-1,sizeof(D));
  D[Start] = 0;

  Q.push(Start);

  while(!Q.empty())
    {
      int Nod = Q.front(); Q.pop();
      for(unsigned int j = 0 ; j < G[Nod].size(); j++)
          {
            int Vecin = G[Nod][j];
            if(D[Vecin] == -1)
              {
                D[Vecin] = D[Nod] + 1;
                Q.push(Vecin);
              }
          }
    }
}

void Print()
{
    for(int i = 1 ; i <= N; ++i)
      fout<<D[i]<<" ";
    fout<<"\n";
}

int main()
{
    Read();
    BFS(S);
    Print();
    return 0;
}