Procedure: STACK concatenation
Method: Hoare's quicksort

Realize these actions:

• Create the stack
• Add the element to the stack (push)
• Pull out the element from the stack (pop)
• Return the topmost element of the stack (top)
• Destroy the stack (destroy)
• Check the emptiness of the stack
• Quick sort

Algoritm includes following:

• Choose a pivot (supporting element)
• Devide stack into two stacks(right and left)
• The elements that are less then pivot we put into right stack, others- to the left stack
• Then we do the previous steps for right and left sctacks
• Concatenate right and left stack and the pivot in the one stack
• Return this stack

• stack_print(Stack* stack)
• stack_sort(Stack* stack)
• stack_concatenate(Stack* right, Stack* left, Item* pivot)

-----
I | O
-----
1 | 1
2 | 2
3 | 3
-----
2 | 1
1 | 2
3 | 3
-----
1 | 1
-----
3 | 1
2 | 2
1 | 3
-----

• Download this folder to your PC
• Type 'make' to compile
• Launch by typing ./start
• Type 'help' to gain the information about the keys to control the app

Here is the keys description:

• 'add' - to insert the value in the stack
• 'print' - to print the stack
• 'destroy' - to delete the stack
• 'sort' - to start sorting the stack with Hoare's quick sort algorithm
• 'exit' or 'quit' - to quit the application