Cod sursa(job #2082367)

Utilizator trifangrobertRobert Trifan trifangrobert Data 6 decembrie 2017 01:34:34
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.82 kb
#include <fstream>
#include <queue>
#include <vector>
#define DIM 100010

using namespace std;

int n, m, s;
vector <int> graf[DIM];
queue <int> q;
bool viz[DIM];
int dist[DIM];

void BFS()
{
	int x; 
	q.push(s);
	viz[s] = true;
	while (!q.empty())
	{
		x = q.front();
		q.pop();
		for (int i = 0;i < (int)graf[x].size();++i)
			if (!viz[graf[x][i]])
			{
				dist[graf[x][i]] = dist[x] + 1;
				q.push(graf[x][i]);
				viz[graf[x][i]] = true;
			}
	}
}

int main()
{
	ifstream fin("bfs.in");
	ofstream fout("bfs.out");
	fin >> n >> m >> s;
	int x, y;
	for (int i = 1;i <= m;++i)
	{
		fin >> x >> y;
		graf[x].push_back(y);
	}
	BFS();
	for (int i = 1;i <= n;++i)
		if (i != s && dist[i] == 0)
			fout << -1 << " ";
		else
			fout << dist[i] << " ";
	fin.close();
	fout.close();
	return 0;
}