Cod sursa(job #2170762)

Utilizator Laura_CorneiLaura Maria Cornei Laura_Cornei Data 15 martie 2018 09:40:21
Problema Stramosi Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.01 kb
#include <fstream>
#include <vector>
#include <math.h>
#define nmax 250005
#define mmax 300005
using namespace std;
fstream f1("stramosi.in", ios::in);
fstream f2("stramosi.out", ios::out);
int n, m, t[nmax], viz[nmax], dp[nmax][25];
vector <int> v[nmax];
void dfs(int nod, int niv)
{
    dp[nod][0]=t[nod];
    for(int j=1; (1<<j)<=niv; j++)
        dp[nod][j]=dp[dp[nod][j-1]][j-1];

    viz[nod]=1;
    for(auto it=v[nod].begin(); it!=v[nod].end(); ++it)
        if(!viz[*it])
           dfs(*it, niv+1);
}
void citire()
{
    int i;
    f1>>n>>m;
    for(i=1; i<=n; i++)
    {
        f1>>t[i];
        v[t[i]].push_back(i);
    }
    dfs(0, 0);
}
void afis()
{
    int i, j, nod, p, rez;
    for(i=1; i<=m; i++)
    {
        f1>>nod>>p;
        rez=nod;
        for(j=20; (j>=0)&&(p>0); j--)
            if(p>=(1<<j))
        {
            rez=dp[rez][j];
            p-=(1<<j);
        }
        f2<<rez<<"\n";
    }
}
int main()
{
    citire();
    afis();
    return 0;
}