Cod sursa(job #645558)

Utilizator titeltitel popescu titel Data 9 decembrie 2011 21:57:35
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.7 kb
# include <cstdio>
# include <vector>
# include <queue>
# define Nmax 100001
using namespace std;
vector<int> v[Nmax];
queue <int> Q;
int n,m,s,x,y,cost[Nmax];
int main()
{freopen ("bfs.in", "r", stdin);
 freopen ("bfs.out", "w", stdout);
 scanf ("%d%d%d", &n, &m ,&s);
 for (int i = 1; i <= m; ++i) 
  {scanf ("%d %d", &x, &y); v[x].push_back(y);}
 for (int i = 1; i <= n; ++i) cost[i]=-1;
 Q.push(s); cost[s]=0;
 while( !Q.empty() ) //3
    {x=Q.front(); Q.pop(); //4
	 for(int i=0; i<v[x].size(); ++i )  //5
		{y=v[x][i];
		 if( cost[y]==-1 )
                 {Q.push(y); cost[y]=cost[x]+1;}
		}
    }
 for (int i = 1; i <= n; ++i) printf("%d ",cost[i]);
 printf("\n");
 return 0;
}