Cod sursa(job #538939)

Utilizator alexluigy007ciofic luigi alexluigy007 Data 22 februarie 2011 09:35:37
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.82 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;
}