Explain what does the following function do void foo (Stack *s) { while(!s rightarrow isEmpty()) { cout Solution This function is written to call a stack which is a recursive data structure. A stack is basically a collection of objects which is based on LIFO(Last In First Out) where the element that is inserted at the last will be deleted first from the stack. To insert an element we use PUSH in a stack and to delete we use POP. TOP represents the top element in the stack. In this program, function foo calls a stack s and in the while loop there is a condition (!s- >isEmpty()) which checks whether the stack is empty or not. If the stack is not empty then the program prints the top element of the stack (cout<top()) and then s->pop(); means that after printing the top element pop opertaion is being called which deletes the top most element of the stack. So this program will delete all the elements of the stack until the stack is empty. Example- the stack has elements inserted as 10,9,8,7. So the program will print 10,9,8,7 and will delete them one by one. First 10 will be deleted then 9 and so on as stack follows a LIFO structure..

1. Explain what does the following function do void foo (Stack *s) { while(!s rightarrow
isEmpty()) { cout
Solution
This function is written to call a stack which is a recursive data structure. A stack is basically a
collection of objects which is based on LIFO(Last In First Out) where the element that is inserted
at the last will be deleted first from the stack. To insert an element we use PUSH in a stack and
to delete we use POP.
TOP represents the top element in the stack.
In this program, function foo calls a stack s and in the while loop there is a condition (!s-
>isEmpty()) which checks whether the stack is empty or not. If the stack is not empty then the
program prints the top element of the stack (cout<top()) and then s->pop(); means that after
printing the top element pop opertaion is being called which deletes the top most element of the
stack.
So this program will delete all the elements of the stack until the stack is empty.
Example- the stack has elements inserted as 10,9,8,7. So the program will print 10,9,8,7 and will
delete them one by one. First 10 will be deleted then 9 and so on as stack follows a LIFO
structure.