Suppose the following stack functions have been implemented for you:

$/*$ Creates$/$Frees a stack of strings Add element $x$ to queue$/$stack Check if stack are empty Remove element from stack $*/$

$x=$pop$(ps)$;

Write a simple function which swaps the contents of two given stacks.

Hint: Use one or more additional stacks to accomplish this.

void swap$($ Stack$*$ a$,$ Stack$*$ b $)\{$