Cod sursa(job #545590)

Utilizator maooBompa Mario maoo Data 3 martie 2011 17:28:05
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.77 kb
#include<cstdio>
#include<vector>
#include<deque>

using namespace std;
vector<int> v[100010];
int n,m,s,a,b,d[100010],i;
deque<int> q;
void read(),solve(),bfs();
int main()
{
	read();
	solve();
	return 0;
}
void read()
{
	freopen("bfs.in","r",stdin);
	freopen("bfs.out","w",stdout);
	scanf("%d%d%d",&n,&m,&s);
	for(;m;m--)
	{
		scanf("%d%d",&a,&b);
		v[a].push_back(b);
	}
}
void solve()
{
	for(i=1;i<=n;i++)
		d[i]=-1;
	d[s]=0;
	q.push_back(s);
	bfs();
	for(i=1;i<=n;i++)
		printf("%d ",d[i]);
	

}
void bfs()
{
	int crt;
	vector<int>::iterator it;
	for(;!q.empty();)
	{
		crt=q.front();
		for(it=v[crt].begin();it!=v[crt].end();it++)
			if(d[*it]==-1)
			{
				d[*it]=d[crt]+1;
				q.push_back(*it);
			}
		q.pop_front();
	}
}