Cod sursa(job #2269290)

Utilizator nicolaefilatNicolae Filat nicolaefilat Data 25 octombrie 2018 20:49:52
Problema Stramosi Scor 80
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.1 kb
#include <iostream>
#include <fstream>

const int MAXN = 250000 + 5,MAXLOG = 17 + 5;

using namespace std;

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

int dp[MAXN][MAXLOG];
int n,q;

int query(int nod,int stramos){
    int ans = 0;
    for(int j = 0; j < MAXLOG; j++){
        if(stramos & (1<<j)){
            if(!dp[nod][j])
                return 0;
            ans = dp[nod][j];
            nod = dp[nod][j];
        }
    }
    return ans;
}

int main()
{
    in>>n>>q;
    for(int i = 1; i <= n; i++){
        int tata;
        in>>tata;
        dp[i][0] = tata;
    }

    for(int put = 1; put <= MAXLOG; put++)
        for(int i = 1; i <= n; i++)
            if(i + (1 << (put - 1)) < MAXN)
                dp[i][put] = dp[dp[i][put - 1]][put - 1];

    for(int i = 1; i <= q; i++){
        int nod,k_stramos;
        in>>nod>>k_stramos;
        out<<query(nod,k_stramos)<<"\n";
    }
    ///stramosul 2 ^ j al lui i este dp[i][j]
    ///dp[i][j] = . dp[i][j - 1] al 2 ^ (j - 1) stramos al lui i
    ///dp[i][j] = dp[dp[i][j - 1][j - 1]
    return 0;
}