#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

typedef struct node
{
	void* dataPtr;
	struct node* link;
} STACK_NODE;

typedef struct
{
	int count;
	STACK_NODE* top;
} STACK;

STACK* createStack()
{
	STACK* stack;

	stack = (STACK*)malloc(sizeof(STACK));
	if (stack)
	{
		stack->count = 0;
		stack->top = NULL;
	}
	return stack;
}

bool pushStack(STACK* stack, void* dataInPtr)
{
	STACK_NODE* newPtr;

	newPtr = (STACK_NODE*)malloc(sizeof(STACK_NODE));
	if (!newPtr)
		return false;

	newPtr->dataPtr = dataInPtr;

	newPtr->link = stack->top;
	stack->top = newPtr;

	(stack->count)++;
	return true;
}

void* popStack(STACK* stack)
{
	void* dataOutPtr;
	STACK_NODE* temp;

	if (stack->count == 0)
		dataOutPtr = NULL;
	else
	{
		temp = stack->top;
		dataOutPtr = stack->top->dataPtr;
		stack->top = stack->top->link;
		free(temp);
		(stack->count)--;
	}
	return dataOutPtr;
}

void* stackTop(STACK* stack)
{
	if (stack->count == 0)
		return NULL;
	else
		return stack->top->dataPtr;
}

bool emptyStack(STACK* stack)
{
	return (stack->count == 0);
}

bool fullStack(STACK* stack)
{
	STACK_NODE* temp;

	if (temp = (STACK_NODE*)malloc(sizeof(stack->top)))
	{
		free(temp);
		return false;
	}

	return true;
}

int stackCount(STACK* stack)
{
	return stack->count;
}

STACK* destroyStack(STACK* stack)
{
	STACK_NODE* temp;

	if (stack)
	{
		while (stack->top != NULL)
		{
			free(stack->top->dataPtr);

			temp = stack->top;
			stack->top = stack->top->link;
			free(temp);
		}

		free(stack);
	}
	return NULL;
}

int main()
{
	STACK* stack;
	int* dataPtr=NULL;
	int i = 0,
		data[2] = { 1, 2};
	bool done = false,
		firstdata = true;

	stack = createStack();

	printf("Enter numbers, <EOF> to stop\n");

	while (!done)
	{
		if (firstdata)
		{
			dataPtr = (int*)malloc(sizeof(int));
			*dataPtr = data[i];
			printf("%d\n", *dataPtr);
			pushStack(stack, dataPtr);
			i++;
			if (i == 2)
			{
				firstdata = false;
			}
		}
		else
		{
			if ((scanf("%d", dataPtr) == EOF) || fullStack(stack))
				done = true;
			else
			{

				while (!emptyStack(stack))
				{
					dataPtr = (int*)popStack(stack);
					printf("%d\n", *dataPtr);
				}

			}
		}
	}
	destroyStack(stack);

	getchar();
	return 0;
}