Cod sursa(job #672683)

Utilizator lucian666Vasilut Lucian lucian666 Data 2 februarie 2012 21:47:49
Problema BFS - Parcurgere in latime Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 0.75 kb
#include<fstream>
#define INF 999999999
using namespace std;
ofstream out("bfs.out");
int a[2500][2500],uz[2500],d[2500],n,m,s,q[2500];
void citire();
void bfs(int start);
int main()
{
	citire();
	bfs(s);
	for(int i=1;i<=n;i++)
		if(d[i]==INF)
			out<<-1<<" ";
		else
		out<<d[i]<<" ";
	return 0;
}
void citire()
{
	ifstream in("bfs.in");
	in>>n>>m>>s;
	int x,y;
	for(;m;m--)
	{
		in>>x>>y;
		a[x][y]=1;
	}
}
void bfs(int start)
{
	int st,dr,k;
	st=dr=1;
	for(int j=1;j<=n;j++)
	{
		d[j]=INF;
	}
	q[dr]=start;
	d[start]=0;
	uz[start]=1;
		while(st<=dr)
		{
			k=q[st];
				for(int i=1;i<=n;i++)
					if(a[k][i]==1&&uz[i]==0)
					{
						++dr;
						q[dr]=i;
						uz[i]=1;
						d[i]=d[k]+1;
					}
					++st;
		}
}