Is this Java palindrome solution efficient? It doesn't use string or char methods

Question

Here's the solution I saw:

package com.philippemoisan;

public class Main {

    public static void main(String[] args) {
        System.out.println(isPalindrome(-212));
    }

    public static boolean isPalindrome(int number)  {
        int reverse  = 0;
        int initNumber = number;
        while (number != 0)  {
            int lastDigit = number % 10;
            reverse = reverse * 10;
            reverse +=lastDigit;
            number/=10;
        }
        if (initNumber == reverse)  {
            return true;
        }
        return false;
    }
}

I know there are palindrome solutions here but I am not that far in my Java course yet. So, I just want to know if the solution I posted here is efficient, or would it a lot better to use the solutions from the thread link I provided.

https://codereview.stackexchange.com/ – Steve Smith Feb 06 '19 at 15:34 — Steve Smith, Feb 06 '19 at 15:34

score 0 · Accepted Answer · answered Feb 06 '19 at 15:36

The solution on the linked answer is more efficient, because if the word is not palindrom, it will not iterate through the entire number/word.

The solution you provided loops through the entire number/word even when the first step can detect that the first and the last digit/char are not identical.

score 0 · Answer 2 · answered Feb 06 '19 at 15:38

The link that u provided is for string palindrome and the program u have posted is for a number palindrome. Palindrome concept is same and that's where similarity ends.

The time and space complexity of a string palindrome is entirely different from an integer palindrome.

Hope that helps.best wishes for ur journey in Java

Is this Java palindrome solution efficient? It doesn't use string or char methods

2 Answers2