Cod sursa(job #798364)

Utilizator marinutzacatana marina marinutza Data 16 octombrie 2012 15:10:09
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.93 kb
#include<fstream>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
struct nod
{
    int nr;
    nod *adr;
};
nod *v[100010];
int ok[100010],a,m,n,d[100010];
void citire()
{
    f>>n>>m>>a;
    for(int i=1;i<=m;i++)
    {

        nod *p;
        int x,y;
        f>>x>>y;
        p=new nod;
        p->nr=y;
        p->adr=v[x];
        v[x]=p;
    }
}
void bfs(int a)
{
    int c[100010];
    int p,u;
    p=u=1;
    c[p]=a;
    ok[a]=1;
    d[u]=d[p]+1;
    while(p<=u)
    {
        a=c[p++];
        for(nod *p=v[a];p;p=p->adr)
        {
            if(ok[p->nr]==0)
            {
                c[++u]=p->nr;
                ok[p->nr]=1;
                d[p->nr]=d[a]+1;
            }
        }
    }
    for(int i=1;i<=n;i++)
        if(ok[i]==1)
            g<<d[i]<<' ';
        else
            g<<-1<<' ';
}
int main()
{
    citire();
    bfs(a);
    return 0;
}