Cod sursa(job #1453897)

Utilizator al.mocanuAlexandru Mocanu al.mocanu Data 24 iunie 2015 23:35:02
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.78 kb
#include <stdio.h>
#include <vector>
#include <queue>
#define MAX 100005
using namespace std;

int n, m, s, i, x, y, aux, dist[MAX], viz[MAX];
vector<int> v[MAX];
queue<int> q;

void bfs();

int main(){
	freopen("bfs.in", "r", stdin);
	freopen("bfs.out", "w", stdout);
	scanf("%d%d%d", &n, &m, &s);
	for(i = 0; i < m; i++){
		scanf("%d%d", &x, &y);
		v[x].push_back(y);
	}
	for(i = 1; i <= n; i++)
		dist[i] = -1;
	q.push(s);
	dist[s] = 0;

	bfs();

	for(i = 1; i <= n; i++)
		printf("%d ", dist[i]);
	printf("\n");

	return 0;
}

void bfs(){
	if(q.empty()) return;

	i = q.front();
	q.pop();
	if(viz[i] != 2){
		viz[i] = 2;
		while(!v[i].empty()){
			aux = v[i].back();
			v[i].pop_back();
			if(!viz[aux]){
				viz[aux] = 1;
				dist[aux] = dist[i] + 1;
				q.push(aux);
			}
		}
	}
	bfs();
}