Issue 2: Create a function to find the second highest number in an array.

[srinivasboga]

Summary:

Create a function to find the second highest number in an array.

Related Pull Request:

This issue is related to PR #2.

Details:

The goal is to implement a method that accepts an array of integers and returns the second highest unique number.

Checklist:

• [x] The method should handle duplicates in the input array.
• [x] If there are fewer than two distinct numbers, the method should indicate that the second highest number cannot be found.
• [x] Provide an efficient solution using Java Streams.

Example Input/Output:

• Input: {5, 13, 4, 21, 13, 27, 2, 59, 59, 34}
• Output: 59 (the second highest number)

Additional Notes:

• Ensure to validate the input for edge cases, such as empty arrays or arrays with only one distinct element.