9.palindrome-number.python3.py

#
# [9] Palindrome Number
#
# https://leetcode.com/problems/palindrome-number/description/
#
# algorithms
# Easy (38.18%)
# Total Accepted:    399.3K
# Total Submissions: 1M
# Testcase Example:  '121'
#
# 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.
# 
# 
# Follow up:
# 
# Coud you solve it without converting the integer to a string?
# 
#
class Solution:
    def isPalindrome(self, x):
        """
        :type x: int
        :rtype: bool
        """
        x = list(str(x))
        low, high = 0, len(x)-1
        while low < high:
            if x[low] != x[high]:
                return False
            low += 1
            high -= 1
        return True