""" The 5-digit number, 16807=75, is also a fifth power. Similarly, the 9-digit number, 134217728=89, is a ninth power. How many n-digit positive integers exist which are also an nth power? """ """ The maximum base can be 9 because all n-digit numbers < 10^n. Now 9**23 has 22 digits so the maximum power can be 22. Using these conclusions, we will calculate the result. """ def solution(max_base: int = 10, max_power: int = 22) -> int: """ Returns the count of all n-digit numbers which are nth power >>> solution(10, 22) 49 >>> solution(0, 0) 0 >>> solution(1, 1) 0 >>> solution(-1, -1) 0 """ bases = range(1, max_base) powers = range(1, max_power) return sum( 1 for power in powers for base in bases if len(str((base ** power))) == power ) if __name__ == "__main__": print(f"{solution(10, 22) = }")