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.
题目:判断一个是否是回文数
思路:很直观的做法,首先计算输入的number的位数,然后从两边分别比较,一旦发现不对称就返回false。
class Solution(object):
def isPalindrome(self, x):
"""
:type x: int
:rtype: bool
"""
if x<0:
return False
digits=1
while(x/digits>=10):
digits*=10
num=x
while(digits>1):
right=num%10
left=num/digits
if right!=left:
return False
else:
num=(num%digits)/10
digits/=100
return True
运行结果:279ms,beat 78% 的solution