Cod sursa(job #2016045)

Utilizator BovisioNitica Ionut Bogdan Bovisio Data 28 august 2017 14:52:35
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.01 kb
#include <stdio.h>
#include <vector>

using namespace std;

#define maxn 100010

int n,m,s,L,cost[maxn],G[maxn],S[maxn];

vector <int> A[maxn];

void Read()
{
    int aux1,aux2;
    freopen("bfs.in","r",stdin);
    freopen("bfs.out","w",stdout);
    scanf("%i %i %i",&n,&m,&s);
    for(int i=1;i<=m;i++)
    {
        scanf("%i %i",&aux1,&aux2);
        A[aux1].push_back(aux2);
    }
    for(int i=1;i<=n;i++)
    {
        G[i] = A[i].size(); // numarul vecinilor
    }
}

void BFS(int nod)
{
    for(int i=1;i<=n;i++)
    {
        cost[i] = -1;
    }

    L = 1;
    cost[nod] = 0;
    S[L] = nod;

    for(int i=1;i<=L;i++)
    {
        for(int j=0;j<G[S[i]];j++)
        {
            if(cost[A[S[i]][j]] == -1)
            {
                L++;
                S[L] = A[S[i]][j];
                cost[S[L]] = cost[S[i]] + 1;
            }
        }
    }
}

int main()
{
    Read();
    BFS(s);
    for(int i=1;i<=n;i++)
        printf("%i ",cost[i]);
    return 0;
}