BinarySearch 0286 Inverse Factorial

Problem statement

https://binarysearch.com/problems/Inverse-Factorial/

Solution

Number of factorials which fit 2**31 limit is not big, we can try them all.

Complexity

It is O(1) here we can say.

Code

class Solution:
    def solve(self, a):
        d = {factorial(x):x for x in range(12)}
        return d.get(a, -1)