HackerRank "The Great XOR"

Hey I found problems on HackerRank is more interesting than ones on LeetCode..

Strategy: observeanalyze bit by bit - DISCRETE THINKING. The idea is like this: if we can XOR any bit in original number X to make that bit into 1 from 0, then any bits following that bit don't matter; and we go check bit by bit. This is also the sln in editorial.

t = int(raw_input())

for i in xrange(t):
    n = int(raw_input())
    j = 0
    cnt = 0
    
    while n > 0:
        if (n&1) == 0:
            cnt += pow(2, j)
        j += 1
        n >>= 1
    print cnt