LeetCode 9. Palindrome Number

 class Solution {

    public boolean isPalindrome(int x) {

        String str = String.valueOf(x);

        int n = s.length();

        for (int i=0; i< n/2; i++) {

            if (str .charAt(i) != str .charAt(n - i - 1))

                return false;

        }

        return true;

    }

}

Time Complexity: O(n)

Space Complexity: O(n)

class Solution {

    public boolean isPalindrome(int x) {

        if(x < 0 || (x != 0 && x % 10 == 0)) return false;

        int reversed = 0;

        while(x > reversed) {

            reversed = reversed * 10 + x % 10;

            x = x / 10;

        }

        return (x == reversed) || (x == reversed / 10);

    }    

}

Time Complexity: O(n)

Space Complexity: O(1)