leetcode之Guess Number Higher or Lower

class Solution(object):
def guessNumber(self, n):
"""
:type n: int
:rtype: int
"""
def GuessNum(low, high):
if guess(low) == 0:
return low
if guess(high) == 0:
return high
if guess((low + high) / 2) == 1:
low = (low + high) / 2 + 1
return GuessNum(low, high - 1)
if guess((low + high) / 2) == -1:
high = (low + high) / 2 - 1
print '1'
return GuessNum(low + 1, high)
if guess((low + high) / 2) == 0:
return (low + high) / 2
return GuessNum(1, n)