Cod sursa(job #2073963)

Utilizator VarticeanNicolae Varticean Varticean Data 23 noiembrie 2017 21:40:03
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.84 kb
#include <bits/stdc++.h>
using namespace std;
ifstream in("bfs.in");
ofstream out("bfs.out");
vector <int> v[100005];
int n,m,s, cost[100005];
queue < int > Q;

void read()
{
     in >> n >> m >> s;
     for(int i=1; i<=m; i++)
     {
          int x,y;
          in >> x >> y;
          v[x].push_back(y);
     }
}
void bfs(int s)
{
     for(int i=1; i<=n; i++) cost[i] = -1;
     Q.push(s); cost[s] =0;
     while( !Q.empty() )
     {
          int head = Q.front();
          Q.pop();
          for(int i=0; i<v[head].size(); i++)
               if( cost[ v[head][i] ] == -1 )
          {
               cost[ v[head][i] ] = cost[head] +1;
               Q.push( v[head][i] );
          }

     }
}
int main()
{
     read();
     bfs(s);

     for(int i=1; i<=n; i++)
          out << cost[i] <<' ';

    return 0;
}