power of (number**reverse of number)

power_of_num_mod.py

# See: https://practice.geeksforgeeks.org/problems/power-of-numbers/1/?ref=self

import functools

_MODNUM = 1000000007

# runs fine w/o lru_cache.
functools.lru_cache(maxsize=_MODNUM, typed=True)
def power(N,R):
    if R == 0:
        return 1
    if R%2==0:
        result = power(N, R//2)%_MODNUM
        return (result**2)%_MODNUM
    else:
        return ((N%_MODNUM) * power(N, R-1))%_MODNUM