Sort a stack using recursion

// C program 
// Sort a stack using recursion
#include <stdio.h>
#include <stdlib.h>

// Define stack node
struct StackNode
{
	int element;
	struct StackNode *next;
};
// Define a custom stack
struct MyStack
{
	struct StackNode *top;
	int size;
};
struct MyStack *newStack()
{
	//Make a stack
	struct MyStack *stack = (struct MyStack *) malloc(sizeof(struct MyStack));
	if (stack != NULL)
	{
		//Set node values
		stack->top = NULL;
		stack->size = 0;
	}
	else
	{
		printf("\nMemory overflow when create new stack\n");
	}
}
//Create a new node of stack
struct StackNode *newNode(int element, struct StackNode *next)
{
	//Make a new node
	struct StackNode *node = (struct StackNode *) malloc(sizeof(struct StackNode));
	if (node == NULL)
	{
		printf("\nMemory overflow when create new stack Node \n");
	}
	else
	{
		node->element = element;
		node->next = next;
	}
	return node;
}
// Returns the status of empty or non empty stacks
int isEmpty(struct MyStack *stack)
{
	if (stack->size > 0 && stack->top != NULL)
	{
		return 0;
	}
	else
	{
		return 1;
	}
}
// Add node at the top of stack
void push(struct MyStack *stack, int element)
{
	// Add stack element
	stack->top = newNode(element, stack->top);
	stack->size++;
}
// return top element of stack
int peek(struct MyStack *stack)
{
	return stack->top->element;
}
// Remove top element of stack
void pop(struct MyStack *stack)
{
	if (isEmpty(stack) == 0)
	{
		struct StackNode *temp = stack->top;
		// Change top element of stack
		stack->top = temp->next;
		// remove previous top
		free(temp);
		temp = NULL;
		stack->size--;
	}
}
void sortedAdd(struct MyStack *stack, int element)
{
	if (isEmpty(stack) == 1 || peek(stack) > element)
	{
		// When stack is empty,  Or top of stack is higher of equal to new insert element
		push(stack, element);
	}
	else
	{
		// Get top element
		int data = peek(stack);
		// Remove top element
		pop(stack);
		sortedAdd(stack, element);
		// add previous element
		push(stack, data);
	}
}
void sortStack(struct MyStack *stack)
{
	if (isEmpty(stack) == 0)
	{
		//When stack not empty
		// Get top element
		int element = peek(stack);
		// Remove top element
		pop(stack);
		sortStack(stack);
		// Add element in sorted way
		sortedAdd(stack, element);
	}
}
// Print element of stack
void printData(struct MyStack *stack)
{
	struct StackNode *temp = stack->top;
	while (temp != NULL)
	{
		// Display element value
		printf("  %d", temp->element);
		temp = temp->next;
	}
	printf("\n");
}
int main()
{
	struct MyStack *stack = newStack();
	// Add the stack element
	push(stack, 4);
	push(stack, 7);
	push(stack, 9);
	push(stack, 2);
	push(stack, 3);
	push(stack, 8);
	push(stack, 5);
	push(stack, 6);
	/*
	Created Stack
	============

	    6 <- Top
	    5
	    8
	    3
	    2
	    9
	    7
	    4

	*/
	printf("\n Before Sort \n");
	printData(stack);
	// Sort operation
	sortStack(stack);
	/*
	Sort Stack
	============
	    2   <- Top
	    3   
	    4   
	    5   
	    6   
	    7   
	    8   
	    9
	*/
	printf("\n After Sort \n");
	printData(stack);
	return 0;
}

Output

 Before Sort
  6  5  8  3  2  9  7  4

 After Sort
  2  3  4  5  6  7  8  9