Cod sursa(job #2427406)

Utilizator leo281099Ionescu Leonard Octavian leo281099 Data 31 mai 2019 19:51:59
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.98 kb
#include <iostream>
#include <fstream>
#include <vector>
#define Nmax 100006
using namespace std;

int viz[Nmax], coada[Nmax], distanta[Nmax];
vector <int> graph[Nmax]; //array de liste
ifstream in("bfs.in");
ofstream out("bfs.out");


int main()
{
	int N, M, S;
	in >> N >> M >> S;
	viz[S] = 1;
	int x, y;
	for (int i = 0; i < M; i++)
	{
		in >> x >> y;
		graph[x].push_back(y);
	}
	for (int i = 1; i <= N; i++)
		distanta[i] = -1;
	distanta[S] = 0;
	coada[1] = S;
	int left, right;
	left = right = 1;
	while (left <= right)
	{
		int index = coada[left];//primul element (cu distanta cea mai mica)
		int lim = graph[index].size();
		for (int i = 0; i < lim; i++)
		{
			int vecin = graph[index][i];
			if (!viz[vecin])
			{
				distanta[vecin] = distanta[index] + 1;
				viz[vecin] = 1;
				coada[++right] = vecin;
			}
		}
		left++;//stergi primul element din coada
	}
	for (int i = 1; i <= N; i++)
	{
		out << distanta[i] << "  ";
	}
	return 0;
}