Sum of Number and Its Reverse

Problem Description

Given a non-negative integer num, return true if num can be expressed as the sum of any non-negative integer and its reverse, or false otherwise.

Key Insights

• A number can be formed by adding a non-negative integer to its reverse.
• The reverse of a number may contain leading zeros when represented as a string.
• Exploring numbers up to num is feasible due to the constraint (0 <= num <= 100,000).

Space and Time Complexity

Time Complexity: O(n * d), where n is the value of num and d is the number of digits in num (at most 6). Space Complexity: O(1), as we only use a constant amount of space.

Solution

To determine if a number can be expressed as the sum of a non-negative integer and its reverse, we can iterate through all possible non-negative integers i from 0 to num. For each integer i, we calculate its reverse and check if the sum of i and its reverse equals num.

1. Loop through each integer i from 0 to num.
2. For each i, calculate its reverse.
3. Check if i + reverse(i) == num.
4. If such an i exists, return true. If the loop completes without finding one, return false.

Code Solutions