Cod sursa(job #703117)

Utilizator alexdmotocMotoc Alexandru alexdmotoc Data 2 martie 2012 11:03:31
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.98 kb
#include <cstdio>
#include <vector>
#include <queue>

using namespace std;

#define maxN 100005
#define PB push_back

int N , M , S , cost[maxN];
bool viz[maxN];

vector <int> lista[maxN];
queue <int> Q;


void bfs (int x)
{
	Q.push (x);
	viz[x] = true;
	
	while (!Q.empty ())
	{
		int nod = Q.front();
		Q.pop ();
		
		for (unsigned int i = 0 ; i < lista[nod].size () ; ++i)
		{
			int nodcur = lista[nod][i];
			
			if (viz[nodcur]) continue;
			
			cost[nodcur] = cost[nod] + 1;
			Q.push (nodcur);
			
			viz[nodcur] = true;
		}
	}
}


int main ()
{
	freopen ("bfs.in" , "r" , stdin);
	freopen ("bfs.out" , "w" , stdout);
	
	scanf ("%d %d %d" , &N , &M , &S);
	
	
	int a , b;
	
	for (int i = 1 ; i <= M ; ++i)
	{
		scanf ("%d %d" , &a , &b);
		
		lista[a].PB (b);
	}
	
	for (int i = 1 ; i <= N ; ++i)
		cost[i] = -1;
	
	cost[S] = 0;
	
	bfs (S);
	
	
	for (int i = 1 ; i <= N ; ++i)
		printf ("%d " , cost[i]);
	
	
	return 0;
}