Cod sursa(job #1775123)

Utilizator Grama911Grama Andrei Grama911 Data 9 octombrie 2016 21:44:20
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1 kb
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include "fstream"
#include "vector"
#include "queue"

using namespace std;

ifstream fin("bfs.in");
ofstream fout("bfs.out");

const int inf = 1000000005;
const int nmax = 100005;


vector<int> graph[nmax];
vector <int>::iterator ii;
queue<int> q;
int dist[nmax];

int main() {
	int n, m, s;
	fin >> n >> m >> s;
	for (int i = 1; i <= m; i++) 
{
		int x, y;
		fin >> x >> y;

		graph[x].push_back(y);
	}

	for (int i = 1; i <= n; i++) 
	{
		if (i != s) {
			dist[i] = inf;
		}
	}

	q.push(s);
	while (!q.empty()) {
		int node = q.front();
		q.pop();

		for (int ii = 0; ii != graph[node].size(); ++ii) 
		{
			if (dist[node] + 1 < dist[graph[node][ii]]) 
			{
				dist[graph[node][ii]] = dist[node] + 1;
				q.push(graph[node][ii]);
			}
		}
	}

	for (int i = 1; i <= n; i++) 
		if (dist[i] == inf)
			fout << "-1 ";
		else
			fout << dist[i] << " ";
	fout << "\n";
	fin.close();
	fout.close();
	return 0;
}