Cod sursa(job #1457444)

Utilizator mariakKapros Maria mariak Data 3 iulie 2015 13:09:39
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.2 kb
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <vector>
#define Maxn 100001

using namespace std;
int n, m , s, i, S[Maxn], G[Maxn], Cost[Maxn], L, x, y;
vector <int> v[Maxn];
void BFS(int nod)
{
    /// Marchez toate noduile ca fiind nevizitate
    memset(Cost, -1, sizeof(Cost));
    L = 1;
    Cost[nod] = 0;
    S[L] = nod;
    /// Elimin pe rand nodurile din coada
    for(int i = 1; i <= L; ++ i)
        for(int j = 0; j < G[S[i]]; ++ j)   /// Parcurg vecinii nodului ce urmeaza sa fie eliminat
        if(Cost[v[S[i]][j]] == -1)
    {
        /// Adaug vecinii nevizitati in coada si le calculez distanta
        S[++ L] = v[S[i]][j];
        Cost[S[L]] = Cost[S[i]] + 1;
    }

}
int main()
{
    freopen("bfs.in", "r", stdin);
    freopen("bfs.out", "w", stdout);
    scanf("%d %d %d", &n, &m, &s);
    /// Citesc arcele si retin vecinii intr-o lista
    for(i = 1; i <= m; ++ i)
    {
        scanf("%d %d", &x, &y);
        v[x].push_back(y);
    }
    /// Aflu pt fiecare nod nr de vecini
    for(i = 1; i <= n; ++ i)
    {
        G[i] = v[i].size();
    }
    BFS(s);

    for(i = 1; i <= n; ++ i)
    printf("%d ", Cost[i]);
    return 0;
}