Cod sursa(job #1988672)

Utilizator Mihai_PredaPreda Mihai Dragos Mihai_Preda Data 4 iunie 2017 10:05:22
Problema Stramosi Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.97 kb
#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

const int nMax = 250005;
const int mMax = 300005;
const int logMax = 20;

int n, m;
int dp[logMax][nMax];
int log[nMax];

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

int Query(int nod, int stramos)
{
    if(stramos >= n)
        return 0;
    if(stramos <= 0)
        return nod;
    return Query(dp[log[stramos]][nod], stramos - (1 << log[stramos]));
}

int main()
{
    ifstream in("stramosi.in");
    ofstream out("stramosi.out");
    in >> n >> m;
    for(int i = 1; i <= n; ++i)
        in >> dp[0][i];
    for(int i = 1; (1 << i) <= n; ++i)
        for(int j = 1; j <= n; ++j)
            dp[i][j] = dp[i-1][dp[i-1][j]];
    int q, p;
    SetLog();
    for(int i = 1; i <= m; ++i)
    {
        in >> q >> p;
        out << Query(q, p) << "\n";
    }
    in.close();
    out.close();
    return 0;
}