Cod sursa(job #1281524)
Utilizator | Data | 3 decembrie 2014 11:57:41 | |
---|---|---|---|
Problema | Ridicare la putere in timp logaritmic | Scor | 10 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.37 kb |
#include <fstream>
using namespace std;
ifstream f("lgput.in");
ofstream g("lgput.out");
int putere(int a,int n)
{
if(n==1) return a;
if(n%2==1) return a*putere((long long)a*a,n/2);
return putere((long long)a*a,n/2);
}
int main()
{
int a,n;
f>>a>>n;
g<<putere(a,n)%1999999973;
return 0;
}
/*
a^n=(a^2)^n/2; daca n e par
a*(a^2)^(2n-1)/2
*/