9_回文数.org

题目

思路

• 整数转字符串，用双指针判断
• 官方-反转后面一半的数字

code

# 双指针
class Solution:
    def isPalindrome(self, x: int) -> bool:
        x = str(x)
        left, right = 0, len(x)-1
        while left < right:
            if x[left]==x[right]:
                left += 1
                right -= 1
            else:
                return False
        return True

# 反转后面一半的数字
class Solution:
    def isPalindrome(self, x: int) -> bool:
        if x < 0 or (x>0 and x%10==0):
            return False
        if x in range(10):
            return True
        revert_number = 0
        while x > revert_number:
            revert_number = x%10 + revert_number*10
            print(revert_number)
            x = x//10
        return x==revert_number or x==revert_number//10