Cod sursa(job #1665284)

Utilizator cordun_cristinaCristina Maria Cordun cordun_cristina Data 26 martie 2016 19:46:46
Problema Stramosi Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.76 kb
#include <iostream>
#include <fstream>

using namespace std;
ifstream f("stramosi.in");
ofstream g("stramosi.out");

const int Nmax = 250005;
int n, m, LCA[20][Nmax], log2[Nmax];

void Precalculate()
{
    for(int i = 2; i <= n; i++) log2[i] = log2[i/2]+1;
    for(int i = 1; (1<<i) <= n; i++)
    {
        for(int j = 1; j <= n; j++)
        {
            LCA[i][j] = LCA[i-1][LCA[i-1][j]];
        }
    }
}

int main()
{
    f>>n>>m;
    for(int i = 1; i <= n; i++)
    {
        f>>LCA[0][i];
    }
    Precalculate();
    int p, q;
    while(m--)
    {
        f>>q>>p;
        while(p)
        {
            int k = log2[p];
            q = LCA[k][q];
            p = p - (1<<k);
        }
        g<<q<<'\n';
    }
    return 0;
}