Given an integer x
, return true
if x
is palindrome integer.
An integer is a palindrome when it reads the same backward as forward.
- For example,
121
is a palindrome while123
is not.
Example 1:
Input: x = 121
Output: true
Explanation: 121 reads as 121 from left to right and from right to left.
Example 2:
Input: x = -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: x = 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.
Constraints:
-
-231 <= x <= 231 - 1
Follow up: Could you solve it without converting the integer to a string?SOLUTION:
class Solution:
def isPalindrome(self, x: int) -> bool:
xx = x
nx = 0
while x > 0:
nx = 10 * nx + x % 10
x = x // 10
return xx == nx
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