Cod sursa(job #1929571)

Utilizator PripasAlexandruIulianPripas Alexandru-Iulian PripasAlexandruIulian Data 17 martie 2017 19:51:33
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.13 kb
#include <stdio.h>
#include <vector>

using namespace std;

#define maxn 100010

int N, M, L, Start;
vector <int> A[maxn];
int G[maxn], S[maxn], Cost[maxn];

void BFS(int nod)
{
	int i, j;

	memset(Cost, -1, sizeof(Cost));  // Marchez toate nodurile ca fiind nevizitate

									 //  Introduc nodul de start in coada
	L = 1;
	Cost[nod] = 0;
	S[L] = nod;

	for (i = 1; i <= L; i++) //  Elimin pe rand nodurile din coada
		for (j = 0; j < G[S[i]]; j++)    //  Parcurg vecinii nodului ce urmeaza sa fie eliminat
			if (Cost[A[S[i]][j]] == -1)
			{
				//  Adaug vecinii nevizitati in coada si le calculez distanta
				S[++L] = A[S[i]][j];
				Cost[S[L]] = Cost[S[i]] + 1;
			}
}

int main()
{
	freopen("bfs.in", "r", stdin);
	freopen("bfs.out", "w", stdout);

	int i, x, y;

	scanf("%d %d %d ", &N, &M, &Start);

	//  Citesc arcele si retin graful sub forma de lista de vecini

	for (i = 1; i <= M; i++)
	{
		scanf("%d %d ", &x, &y);
		A[x].push_back(y);
	}

	for (i = 1; i <= N; i++)
		G[i] = A[i].size();

	BFS(Start);

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

	return 0;
}