PalindromNumber.java

public class Solution {
    public boolean isPalindrome(int x) {
        // Start typing your Java solution below
        // DO NOT write main() function
        if (x < 0) return false;
        int div = 1;
        while (x / div >= 10) {
            div *= 10;
        }
        while (x != 0) {
            int l = x / div;
            int r = x % 10;
            if (l != r) return false;
            x = (x % div) / 10;
            div /= 100;
        }
        return true;
    }
}

public class Solution {
    public boolean isPalindrome(int x) {
        // Start typing your Java solution below
        // DO NOT write main() function
        if (x < 0) return false;
        return x == reverseInt(x);
    }
    public int reverseInt(int i){
        int reversedNum = 0;
        while (i != 0){    
            int last_digit = i % 10;
            reversedNum = reversedNum * 10 + last_digit;
            i = i / 10; 
        }
        return reversedNum;
    }
}