How to Return Every Third Element from a Stack Using Stack ADT

How can we return every third element from a stack using the Stack Abstract Data Type (ADT) specification?

How do we handle cases where the stack has less than three elements or is empty?

Method to Return Every Third Element from a Stack:

To return every third element from a stack, we can utilize the Stack ADT specification as follows:

• Create a temporary stack to store the elements needed to return.
• Initialize a count variable to 0.
• Pop each element from the original stack and increment the count by 1.
• If the count is divisible by 3 (count % 3 == 0), push the element into the temporary stack.
• After iterating through all the elements, the required elements will be in the temporary stack.
• Pop the elements from the temporary stack and print them.

For example, if the original stack contains the elements 1 2 3 4 5 6 7 8 9, the method would output: 7, 4, and 1.

Explanation:

The Stack ADT allows us to implement a method that returns every third element from a stack efficiently. By creating a temporary stack and utilizing the count variable to track the position of elements, we can identify and store the required elements successfully.

Handling cases where the stack has less than three elements or is empty is crucial to ensure the method functions correctly for all scenarios. By considering these edge cases and implementing appropriate checks, we can enhance the reliability and robustness of the method.