Problem 1:

Write a Java class (MyStackApp) to emulate a stack structure using an array. Provide methods for push(), pop(), isEmpty(), peek(), and size(). Use the postfix expression in the text (given below) to test your logic for evaluating the postfix form of the expression..

infix:: (3 * 4 - (2 + 5) ) * 4 / 2

postfix: 3 4 * 2 5 + - 4 * 2 /

Be sure to avoid error situations such as popping an empty stack, and the stack holding more than one item at the completion of the program. (Note: you should pop() the last value on the stack and display it as the final result, This should result in an empty stack).

The following is a Java class that shows how to convert a keyboard character input into an integer value:

public class CharToIntExample2{ public static void main(String args[]) { char c='4'; int a = Character.getNumericValue(c); System.out.println(a); } }

Problem 2:

Using the stack implementation in Problem 1, convert an arithmetic expression from infix notation to postfix notation. The output of your algorithm should be the corresponding string in postfix form.