Cod sursa(job #704245)

Utilizator Adela_BaciuAdela Baciu Adela_Baciu Data 2 martie 2012 17:03:23
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.78 kb
#include<cstdio>
#include<vector>
#include<queue>
using namespace std;

const int N = 100099;

vector <int> a[N];
queue <int> q;
int x0,d[N],n;
void citire()
{
	int x,y,m,i;
	scanf("%d%d%d",&n,&m,&x0);
	for(i=1;i<=m;i++)
	{
		scanf("%d%d",&x,&y);
		a[x].push_back(y);
	}
}
void init()
{
	for(int i=1;i<=n;i++)
		d[i]=-1;
}
void afisare()
{
	for (int i=1;i<=n;i++)
		printf("%d ",d[i]);
}
void bfs(int x0)
{
	int x,y;
	q.push(x0);
	d[x0]=0;
	while(!q.empty())
	{
		x=q.front();
		q.pop();
		for(size_t i=0; i<a[x].size();i++)
		{
			y=a[x][i];
			if(d[y]==-1)
			{
				q.push(y);
				d[y]=1+d[x];
			}
		}
	}
}
int main()
{
	freopen("bfs.in","r",stdin);
	freopen("bfs.out","w",stdout);
	citire();
	init();
	bfs(x0);
	afisare();
	return 0;
}