Cod sursa(job #538951)

Utilizator brunetteGeorgiana Pistol brunette Data 22 februarie 2011 09:44:46
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.87 kb
#include<fstream.h>
#define NM 100001
ifstream in("bfs.in");
ofstream out("bfs.out");
int c[NM],viz[NM],d[NM],n,m,start,li=1,ls;

struct nod{
int x;
nod *next;
};
nod *v[NM];

void add(nod *&l,int x){
nod *n=new(nod);
n->x=x;
n->next=l;
l=n;
}

int c_vida(){ return ls<li;}
void pune(int x){c[++ls]=x;}
void scoate(int &x){x=c[li++];}

void build(){
int i,a,b;
in>>n>>m>>start;
for(i=1;i<=m;i++){
in>>a>>b;
add(v[a],b);
	}
}

void bf(int start){
int a,b;
nod *nc;
pune(start); viz[start]=1;
while(!c_vida()){
 scoate(a);
 nc=v[a];
 while(nc){  b=nc->x;
						 if(!viz[b]){ pune(b);
													viz[b]=1;
													d[b]=d[a]+1;
													}
						 nc=nc->next;
						 }
					}
			 }
int main(){
int i;
build();
bf(start);
for(i=1;i<=n;i++)
 if(d[i]==0 && i!=start)
	d[i]=-1;
for(i=1;i<=n;i++)
 out<<d[i]<<" ";
 return 0;
 }