Cod sursa(job #1035054)

Utilizator fhandreiAndrei Hareza fhandrei Data 18 noiembrie 2013 11:55:10
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.06 kb
// Include
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

// Defintiii
#define pb push_back

// Constante
const int sz = (int)1e5+1;
const int oo = (1<<30)-1;

// Variabile
ifstream in("bfs.in");
ofstream out("bfs.out");

int nodes, edges, startNode;
int dist[sz];

vector<int> graph[sz];
queue<int> bfsQ;

// Main
int main()
{
	in >> nodes >> edges >> startNode;
	
	int rFrom, rTo;
	while(edges--)
	{
		in >> rFrom >> rTo;
		graph[rFrom].pb(rTo);
	}
	
	for(int i=1 ; i<=nodes ; ++i)
		dist[i] = oo;
	
	dist[startNode] = 0;
	
	bfsQ.push(startNode);
	while(!bfsQ.empty())
	{
		int currentNode = bfsQ.front();
		bfsQ.pop();
		vector<int>::iterator it, end=graph[currentNode].end();
		for(it=graph[currentNode].begin(); it!=end ; ++it)
		{
			if(dist[currentNode] + 1 < dist[*it])
			{
				dist[*it] = dist[currentNode] + 1;
				bfsQ.push(*it);
			}
		}
	}
	
	for(int i=1 ; i<=nodes ; ++i)
		out << (dist[i]!=oo? dist[i] : -1) << ' ';
	out << '\n';
	
	in.close();
	out.close();
	return 0;
}