First writing a pseudocode algorithm then translating it into a working Java program. Add comments to explain what the parts are doing.

- What is meant by an array element?

- Present significant differences between Stack and Queue.

- What is infix notation and postfix notation? Show an example for both.

Write a program that uses a stack to reverse the contents of an array of integers. In the main part, ten numbers are prompted to be pushed onto the stack. There is a procedure which is called as 'reverse' in the program for popping the stack and displaying the values in the reverse of the order they were entered in. To develop the program, you can design an function called 'undo' for the user entering the list of numbers. This function could solve the problem when the user enters a wrong number and give another chance to go back and enter the number to replace the last one.

Trace the following pseudocode showing the contents of the stack after each invocation (step) by drawing a diagram of the state of the stack for each invocation.

Declare MyStack as Stack

MyStack.Push (Google home)?

MyStack.Push (Football match)?

MyStack.Pop

MyStack.Pop

MyStack.Push (Google home)?

MyStack.Push (Basketball match)

MyStack.Push (Match results)?

MyStack.Pop

MyStack.Pop

MyStack.Pop