Cod sursa(job #396431)

Utilizator liv182copoiu liviu liv182 Data 15 februarie 2010 12:38:26
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.74 kb
#include<stdio.h>
#include<vector>
#define N 1<<17
using namespace std;
vector<int> a[N];
int n,m,x0,pred[N],d[N];

void citire()
{
	int x,y;
	scanf("%d%d%d",&n,&m,&x0);
	while (m--)
	{
		scanf("%d%d",&x,&y);
		a[x].push_back(y);
	}
	for(int i=0;i<=N;i++)
        d[i]=-1;
}
void bfs()
{
	int p=0,u=0,x,y,coada[N],i;
	coada[u++]=x0;
	d[x0]=0;
	pred[x0]=0;
	while(p!=u)
	{
		x=coada[p++];
 	for(i=0;i<a[x].size();++i)
	{
		y=a[x][i];
		if(d[y]==-1)
		{
			coada[u++]=y;
			d[y]=1+d[x];
			pred[y]=x;
		}
	}
}
}
void afisare()
{
    int i;
    for(i=1;i<=n;i++)
        printf("%d ",d[i]);
}
int main()
{
	
	freopen("bfs.in","r",stdin);
	freopen("bfs.out","w",stdout);
	citire();
	bfs();
	afisare();
	
	
}