Cod sursa(job #2456283)

Utilizator NopeCarp Rafael Nope Data 14 septembrie 2019 09:37:37
Problema Ridicare la putere in timp logaritmic Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.83 kb
#include <bits/stdc++.h>
#define MOD 1999999973
using namespace std;

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

/// a^100 = a^64 * a^32 * a^4
/// 100 (baza 10) = 1100100 (baza 2)

long long P1(long long a , long long n)
{
    long long p =1;
    while (n > 0)
    {
        if (n % 2 == 1) p *= a & MOD;
        n /= 2;
        a *= a & MOD;
    }
    return p;
}

long long P2(long long a , long long n)
{
    long long p = 1 , i;
    long long f[32];
    f[0] = a;
    f[1] = a * a;
    for (i = 1 ; i <= 30 ; i++)
        f[i] = f[i - 1] * f[i - 1] % MOD;
    i = 0;
    while (n > 0)
    {
        if (n % 2 == 1) p = p * f[i] % MOD;
        n /= 2;
        i++;
    }
    return p;
}

int main()
{
    long long a , n;
    fin >> a >> n;
    fout << P2(a , n) << "\n";
    return 0;
}