Cod sursa(job #538942)

Utilizator iordacheinaiordache ina alexandra iordacheina Data 22 februarie 2011 09:37:19
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 fin("bfs.in");
ofstream fout("bfs.out");
int c[NM],viz[NM],n,m,start,li=1,ls,d[NM];

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;
fin>>n>>m>>start;
for(i=1;i<=m;i++){ fin>>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++) fout<<d[i]<<" ";
return 0;
}