Cod sursa(job #677534)

Utilizator danflorian10Stoica Dan danflorian10 Data 10 februarie 2012 12:25:03
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.91 kb
#include<iostream>
#include<fstream>
using namespace std;
 
ifstream in("bfs.in");
ofstream out("bfs.out");
 
int n,m,start,c[100001],viz[100001],li=1,ls,d[1000001];
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>>start;
	int x,y;
	for(int i=1;i<=m;i++){
		in>>x>>y;
		add(x,y);
		}
} 
int cv(){
	return li>ls;
}
void pune(int x){
	ls++;
	c[ls]=x;
} 
void scoate(int &x){
	x=c[li];
	li++;
}
void bf(int start){
	pune(start);
	viz[start]=1;
	while(!cv()){
		int x;
		scoate(x);
		nod *nc=LA[x];
		while(nc){
			int y=nc->info;
			if(!viz[y]){
				pune(y);
				viz[y]=1;
				d[y]=d[x]+1;
				}
			nc=nc->next;
		}
	}	
}
int main(){
	citire();
	bf(start);
	for(int i=1;i<=n;i++)
	if(d[i]==0&&i!=start) d[i]=-1;
	for(int i=1;i<=n;i++)
	out<<d[i]<<" ";
}