码迷,mamicode.com
首页 > 其他好文 > 详细

leetcode 9. Palindrome Number

时间:2018-07-21 14:41:52      阅读:130      评论:0      收藏:0      [点我收藏+]

标签:top   +=   amp   The   des   put   therefore   without   pre   

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.

Follow up:

Coud you solve it without converting the integer to a string?

class Solution(object):
    def isPalindrome(self, x):
        """
        :type x: int
        :rtype: bool
        """
        if x < 0: return False
        s = str(x)
        i, j = 0, len(s)-1
        while i<j:
            if s[i] != s[j]:
                return False
            i += 1
            j -= 1
        return True

 不使用string的话,还是比较巧妙的:

class Solution(object):
    def isPalindrome(self, x):
        """
        :type x: int
        :rtype: bool
        """
        if x < 0: return False
        num = x
        y = 0
        while x != 0:
            y = y*10 + x%10
            x /= 10
        return y == num

 

leetcode 9. Palindrome Number

标签:top   +=   amp   The   des   put   therefore   without   pre   

原文地址:https://www.cnblogs.com/bonelee/p/9346154.html

(0)
(0)
   
举报
评论 一句话评论(0
登录后才能评论!
© 2014 mamicode.com 版权所有  联系我们:gaon5@hotmail.com
迷上了代码!