Cod sursa(job #858199)

Utilizator alexdmotocMotoc Alexandru alexdmotoc Data 18 ianuarie 2013 17:47:27
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.91 kb
#include <iostream>
#include <cstdio>
#include <vector>
#include <cstring>
#include <queue>

using namespace std;

#define maxN 100005
#define PB push_back

vector <int> V[maxN];
queue <int> Q;
bool viz[maxN];
int cost[maxN];

int N , M , S;

int main ()
{
	freopen ("bfs.in" , "r" , stdin);
	freopen ("bfs.out" , "w" , stdout);
	
	scanf ("%d %d %d" , &N , &M , &S);
	
	int a , b;
	
	while (M --)
	{
		scanf ("%d %d" , &a , &b);
		
		V[a].PB(b);
	}
	
	memset (cost , -1 , sizeof (cost));

	Q.push(S);
	cost[S] = 0;
	viz[S] = true;
	
	while (!Q.empty())
	{
		int root = Q.front();
		Q.pop();
		
		for (unsigned int i = 0 ; i < V[root].size() ; ++i)
		{
			int node = V[root][i];
			
			if (viz[node])
				continue;
			
			viz[node] = true;
			cost[node] = cost[root] + 1;
			Q.push(node);
		}
	}
	
	for (int i = 1 ; i <= N ; ++i)
		printf ("%d " , cost[i]);
	
	return 0;
}