#include <stdbool.h>
#ifndef STACK_H_INCLUDED
#define STACK_H_INCLUDED

//push data if the stack is not full
bool push(int newData);

//returns the +ve integer at the 
//top of the stack or -1 if the stack is empty
int peek();

//Removes and returns the +ve integer at the 
//top of the stack or -1 if the stack is empty
int pop();

//returns the current size of the stack
int size();

//returns true if the stack is empty
bool isEmpty();


#endif // STACK_H_INCLUDED

#include <stdbool.h>
#include <stdio.h>
#define MAX_SIZE 10
#include "Stack.h"

int stackData[MAX_SIZE];
int sizeOfStack = 0;

bool push(int newData)
{

    if(sizeOfStack==MAX_SIZE)
    {
        puts("ERROR: Tried to push to a full stack. Operation failed\n");
        return false;
    }
    else
    {
        stackData[sizeOfStack]=newData;//add data to the next available location
        sizeOfStack++;//increment size
        return true;
    }



}

int peek()
{
    if(isEmpty())
    {
        puts("ERROR: Tried to peek at an empty stack. -999999 returned as result\n");
        return-999999;
    }

    else
        return stackData[sizeOfStack-1];//return item at the top of the stack
}

int pop()
{
    if(isEmpty())
    {
        puts("ERROR: Tried to pop an empty stack. -999999 returned as result\n");
        return -999999;
    }
    else
    {
        int result = stackData[sizeOfStack-1];//return item at the top of the stack
        sizeOfStack--;//reduce size
        return result;
    }

}

int size()
{
    return sizeOfStack;
}

bool isEmpty()
{
    return sizeOfStack==0;
}

#include <stdio.h>
#include <stdlib.h>
#include "Stack.h"
int main()
{
    //stack demo
    //try peeing at empty stack
    printf("%d\n",peek());

    //push 100,200,...,1000,1100 (push 11 numbers, 10 should be pushed, 1100 will not be pushed
    push(100);
    printf("%d\n",peek());
    push(200);
    printf("%d\n",peek());
    push(300);
    printf("%d\n",peek());
    push(400);
    printf("%d\n",peek());
    push(500);
    printf("%d\n",peek());
    push(600);
    printf("%d\n",peek());
    push(700);
    printf("%d\n",peek());
    push(800);
    printf("%d\n",peek());
    push(900);
    printf("%d\n",peek());
    push(1000);
    printf("%d\n",peek());
    push(1100);
    printf("%d\n",peek());

    //try displaying the size and popping 11 times.
    //failure expected on the 11th time.
    printf("Size, Pop\n");
    printf("%d\n",size());
    printf("%d\n",pop());
    printf("\n\n");
    printf("Size, Pop\n");
    printf("%d\n",size());
    printf("%d\n",pop());
    printf("\n\n");
    printf("Size, Pop\n");
    printf("%d\n",size());
    printf("%d\n",pop());
    printf("\n\n");
    printf("Size, Pop\n");
    printf("%d\n",size());
    printf("%d\n",pop());
    printf("\n\n");
    printf("Size, Pop\n");
    printf("%d\n",size());
    printf("%d\n",pop());
    printf("\n\n");
    printf("Size, Pop\n");
    printf("%d\n",size());
    printf("%d\n",pop());
    printf("\n\n");
    printf("Size, Pop\n");
    printf("%d\n",size());
    printf("%d\n",pop());
    printf("\n\n");
    printf("Size, Pop\n");
    printf("%d\n",size());
    printf("%d\n",pop());
    printf("\n\n");
    printf("Size, Pop\n");
    printf("%d\n",size());
    printf("%d\n",pop());
    printf("\n\n");
    printf("Size, Pop\n");
    printf("%d\n",size());
    printf("%d\n",pop());
    printf("\n\n");
    printf("Size, Pop\n");
    printf("%d\n",size());
    printf("%d\n",pop());
    printf("\n\n");


    return 0;
}