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
Runtime 16ms Memory 12.42 MB
def isPalindrome(self, x):
"""
:type x: int
:rtype: bool
"""
num = x
if x < 0:
return False
else:
rev = 0
while x > 0:
rev = rev * 10 + x % 10
x = x//10
return rev==num