Cod sursa(job #2185844)

Utilizator savigunFeleaga Dragos-George savigun Data 24 martie 2018 22:44:13
Problema Stramosi Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.93 kb
#include <iostream>
#include <fstream>
using namespace std;

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

const int L = 1 << 17;
const int MAXN = 250005;
int n, m, log[MAXN];
int dp[18][MAXN];

void preprocess() {
    log[1] = 0;
    for (int i = 2; i <= n; ++i) {
        log[i] = log[i / 2] + 1;
    }

    for (int j = 1; j <= 17; ++j) {
        for (int i = 1; i <= n; ++i) {
            dp[j][i] = dp[j - 1][dp[j - 1][i]];
        }
    }
}

int query(int x, int k) {
    int mask = 1 << log[k];
    for (int i = log[k]; i >= 0; --i) {
        if ((mask & k) != 0) {
            x = dp[i][x];
        }
        mask >>= 1;
    }
    return x;
}


int main()
{

    in >> n >> m;
    for (int i = 1; i <= n; ++i) in >> dp[0][i];
    preprocess();

    for (int i = 1; i <= m; ++i) {
        int x, k;
        in >> x >> k;
        out << query(x, k) << "\n";
    }

    return 0;
}