1104. Path In Zigzag Labelled Binary Tree

class Solution(object):
    def pathInZigZagTree(self, label):
        x=-1
        while pow(2,x)<=label:
            x+=1
        ans=[]
        i=0
        x-=1
        while i<=x:
            ans.append(label)
            label=pow(2,x-i-1)*3 -label//2-1
            i+=1
        return ans[::-1]