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#!/usr/bin/env python

'''

Leetcode: Palindrome number

Determine whether an integer is a palindrome. Do this without extra space.

* Should be interesting if it is a float, but it is hard to determine the accuracy

http://leetcode.com/2012/01/palindrome-number.html

'''

from __future__ import division

import math

# number with k digit

# 10**(k-1) <= num < 10**k

def pali_num(num):

print 'Check:', num,

if num < 0: return False

if num == 0: return True

k = int(math.log10(num)) + 1

base = 10**(k-1)

while num > 0 and base > 1:

# left-most digit?

left = num // base

num -= left*base

base /= 100

# right-most digit?

right = num % 10

num = num // 10

if left != right: return False

return True

if __name__ == '__main__':

print pali_num(12345)

print pali_num(12321)

print pali_num(123321)

print pali_num(1236666321)

print pali_num(-1)

print pali_num(-0)

print pali_num(0)