Cod sursa(job #557593)

Utilizator tinkyAndrei Ilisei tinky Data 16 martie 2011 18:39:59
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.71 kb
#include<fstream>
#include<vector>
#include<queue>
#define pb push_back
using namespace std;
vector<int> v[100001];
queue<int> q;
int n,m,s,viz[100001];
void citire()
{
	int i,x,y;
	ifstream in("bfs.in");
	in>>n>>m>>s;
	for (i=1;i<=m;i++)
	{
		in>>x>>y;
		v[x].pb(y);
	}
}
void bfs(int p)
{
	int x,y,i;
	q.push(p);
	while (!q.empty())
	{
		x=q.front();
		q.pop();
		for (i=0;i<(int)v[x].size();i++)
		{
			y=v[x][i];
			if (!viz[y]&&y!=p)
			{
				viz[y]=viz[x]+1;
				q.push(y);
			}
		}
	}
}
void afisare()
{
	int i;
	ofstream out("bfs.out");
	for (i=1;i<=n;i++)
		if (viz[i]||i==s)
			out<<viz[i]<<" ";
		else
			out<<"-1 ";
}
int main()
{
	citire();
	bfs(s);
	afisare();
}