Cod sursa(job #368502)

Utilizator mihaimoldovanMihai Moldovan mihaimoldovan Data 25 noiembrie 2009 08:10:22
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.82 kb
#include<fstream>
using namespace std;
#define max 100001
struct nod{
	int info;
	nod *next;
	};
nod *a[max];
int n,d[max],s;
void read()
{
	ifstream fin("bfs.in");
	int m,i,j;
	fin>>n>>m>>s;
	for(int i=1;i<=n;i++)
		{
			a[i]=NULL;
			d[i]=-1;
		}
	for(;m;m--)
	{
		fin>>i>>j;
		nod *p=new nod;
		p->info=j;
		p->next=a[i];
		a[i]=p;
	}
}
void bfs()
{
	nod *st,*dr;
	int k;
	st=dr=new nod;
	dr->info=s;
	dr->next=NULL;
	d[s]=0;
	while(st!=NULL)
	{
		k=st->info;
		for(nod*p=a[k];p!=NULL;p=p->next)
			if(d[p->info]==-1)
			{
				nod *q=new nod;
				q->info=p->info;
				p->next=NULL;
				dr->next=p;
				dr=p;
				d[p->info]=d[k]+1;
			}
		nod*t=st;	
		st=st->next;
		delete t;
			
	}
}
void write()
{
	ofstream fout("bfs.out");
	for(int i=1;i<=n;i++)
		fout<<d[i]<<" ";
	fout.close();
}
int main()
{
	read();
	bfs();
	write();
	return 0;
}