Q$2)($a$)$ Write a function: $$reverseStack$($Stack st$),$ which prints the contents of the stack st in reverse $($i$.$e$.,$ the top of the stack is printed last$).$

You are allowed only to use another stack, $$Stack st$2.$ That is$,$ you cannot use any arrays etc. The only functions you can use on stacks are pop$(),$ push$()$ and empty$().($Hint: You put the contents of one stack into another by popping and pushing. Is the order the same?$)$

$($b$)$ Let n be the length of the input stack. Let k be the total number of times you had to push and pop from the two stacks. Express k in terms of n$.$ What is the complexity of this reversing algorithm in O$-$notation?