Cod sursa(job #3253696)

Utilizator iuliageambazuGeambazu Iulia iuliageambazu Data 4 noiembrie 2024 14:53:29
Problema Stramosi Scor 80
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.82 kb
#include <bits/stdc++.h>
#define int long long

using namespace std;

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

const int NMAX=250000, LOGMAX=20;
int n,m;
vector<int>t(NMAX+5);
vector<vector<int>> anc(NMAX+5, vector<int>(LOGMAX+5)); /// anc[i][j]=al 2^j-lea stramos al lui i


signed main()
{
    fin>>n>>m;
    for(int i=1;i<=n;i++)
    {
        fin>>anc[i][0];
    }
    for(int i=1; i<=LOGMAX;i++)
        for(int j=1;j<=n;j++)
        anc[j][i]=anc[anc[j][i-1]][i-1];
    for(int i=1;i<=m;i++)
    {
        int x,y;
        fin>>x>>y;
        for(int j=LOGMAX;j>=0;j--)
            if((1<<j)<=y)
        {
            x=anc[x][j];
            y-=(1<<j);
        }
        if(x==0)
            fout<<0<<'\n';
        else
            fout<<x<<'\n';
    }

    return 0;
}