leecode---09---Number, take the remainder and divide it---determine whether a number is a palindrome

https://leetcode.com/problems/palindrome-number/description/

 

meaning of the title

Determine if a number is a palindrome

 

 

analyze

32132132100

              /100

delete the 0 part

             %100

leave the part of 0

 

 

code

class Solution {

    public boolean isPalindrome(int x) {

        if (x < 0) return false;

        

        //calculate to the highest bit of x

        int div = 1;

        while (div * 10 <= x) {

            div = div * 10;

        }

        

        // Each time the first and last bits are taken out for judgment

        //Reduce two digits after judgment

        while (x != 0) {

            int left = x /div;

            int right = x % 10;

            if (left != right) return false;

            // Take the remainder and keep the last bit, and divide it to keep the front bit

            x = (x%div) / 10;

            div /= 100;

        }

        return true;

    }

}