Cod sursa(job #505857)

Utilizator alinabBlaj Alina alinab Data 4 decembrie 2010 11:17:59
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.96 kb
#include <fstream>

using namespace std;

const int Lg  = 100001;

ifstream fin ("bfs.in");
ofstream fout ("bfs.out");

struct nod
{
    int inf;
    nod *urm;
};

nod *g[Lg];

int n, m, s, st[Lg], sf, viz[Lg], lg[Lg];

void add(int x, int y)
{
    nod *aux = new nod;
    aux->inf = y;
    aux->urm = g[x];
    g[x] = aux;
}

void citire()
{
    fin>>n>>m>>s;
    int x, y;
    for (int i=0;i<m;i++)
    {
        fin>>x>>y;
        add(x,y);
    }
}

void bfs()
{
    viz[s]=1;
    st[0]=s;
    sf=1;
    for (int i=1; i<=n; i++)
        lg[i]=-1;
    lg[s]=0;
    for (int i=0;i<sf;i++)
        for (nod *j=g[st[i]];j;j=j->urm)
            if (viz[j->inf]==0)
            {
                viz[j->inf]=1;
                st[sf++]=j->inf;
                lg[j->inf]=lg[st[i]]+1;
            }
}

int main()
{
    citire();
    bfs();
    for (int i=1; i<=n; i++)
        fout<<lg[i]<<" ";
    fout<<"\n";
    return 0;
}