Cod sursa(job #673329)

Utilizator comananamariaComan Ana-Maria comananamaria Data 4 februarie 2012 12:16:42
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.95 kb
#include<fstream>

using namespace std;

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

int n,m,S,coada[100001],viz[100001],li,ls,d[100001];

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

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

int extrage(){
	int x=coada[li];
	li++;
	return x;
}

struct nod{
	int info;
	nod *next;
};

nod *LA[100001];

void add(int x, int y){
	nod *n=new(nod);
	n->info=y;
	n->next=LA[x];
	LA[x]=n;
}

void citire(){
	in>>n>>m>>S;
	for(int i=1;i<=m;i++){
		int x,y;
		in>>x>>y;
		add(x,y);
	}
}

void bf(int start){
	pune(start);
	viz[start]=1;
	while(!cv()){
		int x=extrage();
		nod *nc=LA[x];
		while(nc){
			int y=nc->info;
			if(viz[y]==0){
				pune(y);
				viz[y]=1;
				d[y]=d[x]+1;
			}
			nc=nc->next;
		}
	}
}

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