task1.c

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include "task1a.h"

Stack* init(int size)
{
    Stack*s = (Stack*)malloc(sizeof(Stack));
    if(!s)// if malloc fails
    {
        printf(" Error -- Unalble to allocate memory , terminating the program\n");
        abort();
    }

    s->data = (int*)malloc(sizeof(int) * size); //allocation of the array for the stack

    if(!s->data)
    {
        printf(" Error -- Unalble to allocate memory , terminating the program\n");
        abort();
    }

    s->top = -1;
    s->size = size;
    return s;

}


void push(Stack *s, int element)
{

   if(s->top == s->size -1)
    {
        s->data = realloc(s->data, s->size*2*sizeof(int));
        if (!s->data)
        {
            free(s->data);
            perror("realloc");
        }
        s->size *= 2;
    }

    s->data[++s->top] = element;
}


int pop(Stack* s)
{
    if(isEmpty(s))
    {
        printf("Stack is empty");
        abort();
    }
    else
    {
        return s->data[s->top--];
    }
}

bool isEmpty(Stack *s)
{
    if (s->top == -1)
    {
        return true;

    }
    else
    {
        return false;

    }
}


void destroy (Stack *s)
{
    free(s->data);
    free(s);
}