9. Palindrome Number

 Given an integer x, return true if x is a palindrome, and false otherwise.

 

Example 1:

Input: x = 121
Output: true
Explanation: 121 reads as 121 from left to right and from right to left.

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.

JAVA

Class Solution {
    public boolean isPalindrome(int x) {
        if (x < 0) return false;
        int y = 0, t = x;
        while (t != 0) {
            y = y * 10 + t % 10;
            t /= 10;
        }
        return x == y;
    }
}

C++

class Solution {
public:
    bool isPalindrome(int x) {
        if (x < 0) return false;
        long long a = x, b = 0;
        while (x) {
            b = b * 10 + x % 10;
            x /= 10;
        }
        return a == b;
    }
};

PYTHON

class Solution:
    





    def isPalindrome(self, x: int) -> bool:
        if x < 0:
            return False
        y, t = 0, x
        while t:
            y = y * 10 + t % 10
            t //= 10
        return x == y

JAVASCRIPT

    





    var isPalindrome = function (x) {
    let str = x + '';
    let left = 0,
        right = str.length - 1;
    while (left < right) {
        if (str[left] != str[right]) return false;
        left++;
        right--;
    }
    return true;
};