[LeetCode] Palindrome Number

Given an integer x, return true if x is palindrome integer.

An integer is a palindrome when it reads the same backward as forward. For example, 121 is palindrome while 123 is not.

 

Example 1:Input: x = 121 Output: true

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.

Example 4:

Input: x = -101 Output: false

 

Constraints:

• -231 <= x <= 231 - 1

class Solution {
public:
    bool isPalindrome(int x) {
        string s = to_string(x);
        int m = floor((s.length() + 1) / 2);
        m = (s.length() % 2 == 0 ? m : m - 1);
        for (int i = 0; i < m; i++)
        {
            if (s[i] != s[(s.length() - 1) - i]) return false;
        }
        return true;
    }
};