Cod sursa(job #556656)

Utilizator CosminDDorcu Cosmin CosminD Data 16 martie 2011 11:29:05
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.67 kb
#include <fstream>
#include <vector>
#include <queue>
#define max 100001
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
vector <int> a[max];
queue <int> q;
char viz[max];
int d[max],n,m,k;

int main()
{
	int i,h1,h2,w;
	fin>>n>>m>>k;
	for (i=1;i<=m;i++)
	{
		fin>>h1>>h2;
		a[h1].push_back(h2);
	}
	
	q.push(k); viz[k]=1;
	while (!q.empty())
	{
		w=q.front(); q.pop();
		for (i=0;i<a[w].size();i++)
			if (viz[a[w][i]]==0)
			{
				viz[a[w][i]]=1;
				d[a[w][i]]=d[w]+1;
				q.push(a[w][i]);
			}
		
	}
	
	for (i=1;i<=n;i++)
		if (d[i]==0 && i!=k) fout<<-1<<' ';
	else fout<<d[i]<<' ';
		
	fout.close();
	return 0;
}