python C++遞迴函數解Leetcode779 K th Symbol in Grammar

python C++遞迴函數解Leetcode779 K th Symbol in Grammar 

[code on Leetcode]https://leetcode.com/problems/k-th-symbol-in-grammar/solutions/4205351/c-c-python-recursion-independent-of-n-one-line-0ms-beats-100/

Python code請看

class Solution:
    def kthGrammar(self, n: int, k: int) -> int:
        def f(k):
            if k==1: return 0
            b=(int)(math.log2(k)) # same as b=k.bit_length()-1
            if k==1<<b: return b%2
            else: return 1-f(k-(1<<b))
        return f(k)