Cod sursa(job #1326641)

Utilizator margikiMargeloiu Andrei margiki Data 25 ianuarie 2015 19:38:37
Problema Stramosi Scor 80
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.02 kb
# include <fstream>
# include <algorithm>
# include <vector>
# define N 250005
# define M 300005
using namespace std;
ifstream f("stramosi.in");
ofstream g("stramosi.out");
vector <int> v[N];
struct elem
{
    int ord, q;
}E;
vector <elem> querry[M];
int i,j,n,m,x,y,VV;
int st[N], sol[M];
bool in[N];
void DFS (int k)
{
    vector <elem>::iterator jt;
     st[++VV]=k;
    for (jt=querry[k].begin(); jt<querry[k].end(); ++jt)
    {
        if ((*jt).q>=VV) sol[(*jt).ord]=0;
        else sol[(*jt).ord]=st[VV-(*jt).q];
    }
    vector <int>::iterator it;
    for (it=v[k].begin(); it<v[k].end(); ++it)
        DFS(*it);
    --VV;
}
int main ()
{
    f>>n>>m;
    for (i=1; i<=n; ++i)
    {
        f>>x; v[x].push_back(i);
        if (x!=0) in[i]=1;
    }
    for (i=1; i<=m; ++i)
    {
        f>>x>>y;
        E.ord=i; E.q=y;
        querry[x].push_back(E);
    }

    for (i=1; i<=n; ++i)
        if (! in[i]) DFS(i);

    for (i=1; i<=m; ++i)
        g<<sol[i]<<"\n";

    return 0;
}