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.
分析：
第一反应是先翻转再看是否相等。
代码：
class Solution:
def reverse(self, x: int) -> int:
result = 0
if x > 0 :
while(x):
result = result * 10 + x % 10
x //= 10
#print("x:", x)
#print("result:", result)
if result < -2147483647 or result > 2147483647:
result = 0
return result
def isPalindrome(self, x: int) -> bool:
if x < 0:
return False
y = self.reverse(x)
if x == y:
return True
else:
return False
