leetcode 9: Palindrome Number

题目：

Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.

Example 1:

Input: 121
Output: true

Example 2:

Input: -121
Output: false
Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.

Example 3:

Input: 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.

解答：

如下，第一种方法多一行，但是str(x)只计算了一次，会比第二种形式快一点

class Solution:
    def isPalindrome(self, x):
        """
        :type x: int
        :rtype: bool
        """
        x = str(x)
        if x==x[::-1]:
            return True
        else:
            return False

class Solution:
    def isPalindrome(self, x):
        """
        :type x: int
        :rtype: bool
        """
        if str(x)==str(x)[::-1]:
            return True
        else:
            return False