Cod sursa(job #695798)

Utilizator Ast09Stoica Anca Ast09 Data 28 februarie 2012 14:51:27
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.71 kb
#include<fstream>
#include<queue>
using namespace std;

ifstream f("bfs.in");
ofstream g("bfs.out");

int n,m,s,w,a,b,i,c[100005],viz[100005];
struct nod
{
	int x;
	nod *next;
}	*v[100005],*p;
queue<int> q;

int main()
{
	f>>n>>m>>s;
	
	for(i=1;i<=m;i++)
	{
		f>>a>>b;
		p=new nod;
		p->x=b;
		p->next=v[a];
		v[a]=p;
	}
	
	q.push(s);
	viz[s]=1;
	
	while(!q.empty())
	{
		w=q.front();
		p=v[w];
		q.pop();
		
		while(p)
		{
			if(!viz[p->x])
			{
				c[p->x]=c[w]+1;
				viz[p->x]=1;
				q.push(p->x);
			}
			p=p->next;
		}
	}
	
	for(i=1;i<=n;i++)
	{
		if(c[i]) g<<c[i]<<' ';
		else if(i==s) g<<0<<' ';
			else g<<-1<<' ';
	}
	
	f.close();
	g.close();
	return 0;
}