Cod sursa(job #1391003)

Utilizator AlexandraaaaMereu Alexandra Alexandraaaa Data 17 martie 2015 15:45:28
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.89 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#define max 100005

using namespace std;

ifstream f("bfs.in");
ofstream g("bfs.out");
int v, s, nr[max];
vector <int> G[max];

void bf() {
	int i, j, grad[max];
	for (i = 1; i <= v; i++) {
		grad[i] = G[i].size();
	}
	queue <int> Coada;
	nr[s]++;
	for (i = 0; i < grad[s]; i++)
		if (nr[G[s][i]] == -1) {
			Coada.push(G[s][i]);
			nr[G[s][i]] = 1;
		}
	while (!Coada.empty()) {
		j = Coada.front();
		Coada.pop();
		for (i = 0; i < grad[j]; i++)
			if (nr[G[j][i]] == -1) {
				Coada.push(G[j][i]);
				nr[G[j][i]] = nr[j] + 1;
			}
	}
}

int main()
{
	int i, e, x, y;
	f >> v >> e >> s;
	for (i = 1; i <= e; i++) {
		f >> x >> y;
		G[x].push_back(y);
	}
	for (i = 1; i <= v; i++)
		nr[i] = -1;
	bf();
	for (i = 1; i <= v; i++)
		g << nr[i] << " ";
	f.close();
	g.close();
	return 0;
}