Cod sursa(job #430560)

Utilizator vlad.doruIon Vlad-Doru vlad.doru Data 31 martie 2010 10:08:43
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.65 kb
# include <fstream>
# include <vector>

using namespace std;

ifstream in("bfs.in");
ofstream out("bfs.out");

vector<int>a[1<<17];

int n,coada[1<<17],d[1<<17],p=0,u=0,s;

void citire(){
    int x,y,m;
    in>>n>>m>>s;
    while(m--){
        in>>x>>y;
        a[x].push_back(y);
    }
}

void bfs(int x){
	int i;
	coada[u++]=x;
	d[x]=0;
	while(p!=u){
		x=coada[p++];
		for(i=0;i<a[x].size();i++){
			if(d[a[x][i]]!=-1)
				continue;
			coada[u++]=a[x][i];
			d[a[x][i]]=d[x]+1;
		}
	}
}
	
int main(){
	int i;
	citire();
	for(i=1;i<=n;++i)
		d[i]=-1;
	bfs(s);	
	for(i=1;i<=n;i++){
		out<<d[i]<<" ";
	}
	return 0;
}