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

typedef struct StackNode {
	/*metadata node of stack*/
	int* data;  //point to an array
	int top;
	int maxsize;
} StackNode, *Stack;

Stack createStack(int maxsize);
bool isEmpty(Stack stack);
bool isFull(Stack stack);
bool push(Stack stack, int element);
int pop(Stack stack);
void destroyStack(Stack stack);

int main(int argc, char* argv[]) {
	/*Implement stack by using of array*/
	Stack stack = createStack(10);
	push(stack, 32);
	push(stack, 16);
	push(stack, 20);
	push(stack, 18);
	printf("top = %d\n", stack->top);
	printf("popped value = %d\n", pop(stack));	
	printf("top = %d\n", stack->top);
	return 0;
}

Stack createStack(int maxsize) {
	/*create a new stack*/
	Stack stack = (Stack)malloc(sizeof(StackNode));
	stack->data = (int*)malloc(sizeof(int) * maxsize);
	stack->top = -1;
	stack->maxsize = maxsize;
	return stack;
}

bool isEmpty(Stack stack) {
	/*the stack is empty?*/
	return stack->top == -1;
}

bool isFull(Stack stack) {
	/*the stack is full?*/
	return stack->top == stack->maxsize - 1;
}

bool push(Stack stack, int element) {
	/*push element to the stack*/
	if (isFull(stack)) {
		printf("Ths stack is full!\n");	
		return false;
	} else {
		(stack->data)[++stack->top] = element;
		return true;
	}
}

int pop(Stack stack) {
	/*pop the element*/
	if (isEmpty(stack)) {
		printf("Ths stack is empty!");
		return 99999;
	} else {
		return (stack->data)[stack->top--];
	}
}

void destroyStack(Stack stack) {
	/*destroy the stack*/
	free(stack->data);
	stack->data = NULL;
	free(stack);
	stack = NULL;
}