Palinedrome Number

Jin Shang bio photo By Jin Shang

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.


1) If x is negative, return false;

2) Create x’s inverse. Be careful with overflow!

3) Check if inverse == x;

class Solution {
    bool isPalindrome(int x) {
        if(x<0) return false;
        int z = x;
        int y = 0;
            if(y < (INT_MAX-(x%10))/10){
                y *= 10;
                y += x%10;
                return false;
            x /= 10;
        return z==y;