(a) Define the methods, push and pop that appear in the ADT for Stack. [2] (b) Extend the ADT for Stack by defining a method peek which is similar but different from pop. (e) Suppose that a stack, s, is created by pushing the integers 1, 2 and 3 onto an empty stack in that order: 131 s = 121 [1] /// Sketch the structure of s after the following code is executed: s.pop() s.push(s.peek()) [2] (d) An intermixed sequence of push and pop operations are performed on an initially empty stack. The pushes push the integers 0 through 9 in order and the pops print out the return value. Write down the sequence of push and pop operations that will produce the following output: 2 5 6 7 4 8 9 3 10 (e) Convert the following infix expression to a postfix expression and then explain how to evaluate such a postfix expression using a stack. (3 + 5) / 4 10 / (4 + 2 * 3) [2] 151