Cod sursa(job #676757)

Utilizator sebe14Moraru Sebastian sebe14 Data 9 februarie 2012 16:18:01
Problema BFS - Parcurgere in latime Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 0.77 kb
#include<fstream>
using namespace std;

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

int n,m,a[2600][2600],v[2600],c[2600],li=1,ls,d[2600],start;

void citire(){
	int i,x,y;
	in>>n>>m>>start;
	for(i=1; i<=m; i++){
		in>>x>>y;
		a[x][y]=1;
	}
}

void pune(int x){
	ls++;
	c[ls]=x;
}

void scoate(int &x){
	x=c[li];
	li++;
}

int coada_vida(){
	if(li>ls)
		return 1;
	return 0;
}

void bf(int start){
	v[start]=1;
	pune(start);
	while(!coada_vida()){
		int x;
		scoate(x);
		for(int i=1; i<=n; i++)
			if(a[x][i] and !v[i]){
				v[i]=1;
				pune(i);
				d[i]=d[x]+1;
			}
	}
}

int main(){
	citire();
	bf(start);
	for(int i=1; i<=n; i++)
		if(d[i]==0 and i!=start)
			d[i]=-1;
	for(int i=1; i<=n; i++)
		out<<d[i]<<" ";
	return 0;
}