原题地址：https://oj.leetcode.com/problems/palindrome-number/
题意：
Determine whether an integer is a palindrome. Do this without extra space.
Could negative integers be palindromes? (ie, -1)
If you are thinking of converting the integer to string, note the restriction of using extra space.
You could also try reversing an integer. However, if you have solved the problem "Reverse Integer", you know that the reversed integer might overflow. How would you handle such case?
There is a more generic way of solving this problem.
解题思路：不允许用额外空间，所以不能将数转换成字符串来判断。这里有一种精巧的解决方式。
代码：
class Solution: # @return a boolean def isPalindrome(self, x): if x < 0: return False div = 1 while x/div >= 10: div = div * 10 while x: left = x / div right = x % 10 if left != right: return False x = ( x % div ) / 10 div = div / 100 return True
[leetcode]Palindrome Number @ Python,布布扣,bubuko.com
[leetcode]Palindrome Number @ Python
原文：http://www.cnblogs.com/zuoyuan/p/3779398.html