Cod sursa(job #1424425)

Utilizator MailatMailat Radu Mailat Data 24 aprilie 2015 12:52:25
Problema Ridicare la putere in timp logaritmic Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 0.65 kb
#include <fstream>
#define rest 1999999973
#define ll long long int
using namespace std;

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

/*ll pow(ll x, ll n)
{
    if(n == 0) return 1;
    else if(n == 1) return x;
    else if(n%2 != 0) return x * pow(x*x, (n-1)/2);
    else return pow(x*x, n/2);
}
*/

ll PutereLogaritmic(ll x, ll n)
{
	ll p = 1 ;
	while (n > 0)
	{
		if (n & 1) // n este impar
		{
			p *= x;
			n-- ;
		}
		x = x * x ;
		n >>= 1 ; // sau n = n / 2
	}
	return p ;
}

int main()
{
    ll x, n;
    ll rez;

    fin >> x >> n;
    rez = PutereLogaritmic(x,n);
    fout << rez%rest;
    return 0;
}