Cod sursa(job #301191)

Utilizator whiskeyOzzy Osbourne whiskey Data 7 aprilie 2009 23:39:21
Problema BFS - Parcurgere in latime Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 0.92 kb
#include <iostream>
#include <list>
#include <queue>
#include <vector>
using namespace std;
#define pb push_back

int n;
vector< list<int> > vecini;
vector<int> dist;
vector<bool> sel;
queue<int> c;

void bfs()
{
	int i;
	list<int>::iterator it, sfarsit;
	for (; !c.empty(); c.pop())
	{
		i = c.front();
		sfarsit = vecini[i].end();
		for (it = vecini[i].begin(); it != sfarsit; ++it)
		{
			if (!sel[*it])
			{
				sel[*it] = 1;
				dist[*it] = dist[i] + 1;
				c.push(*it);
			}
		}
	}
}

int main()
{
	freopen("bfs.in", "r", stdin);
	freopen("bfs.out", "w", stdout);

	int i, m, s, x, y;
	cin >> n >> m >> s;
	vecini.resize(n + 1);
	dist.resize(n + 1, -1);
	sel.resize(n + 1, 0);
	for (i = 1; i <= m; ++i)
	{
		cin >> x >> y;
		vecini[x].pb(y);
	}
	c.push(s);
	dist[s] = 0;
	sel[s] = 1;
	bfs();

	for (i = 1; i <= n; ++i)
	{
		cout << dist[i] << ' ';
	}
	cout << '\n';
	return 0;
}