Question

// Whenever i am increasing function call times of push more than 8, it get crashed before that everything is working good. your help is required. In the below code i have created a program for stack using Dynamic array keeping in mind there should not be any stack overflow by using realloc function to doubling the values whenever the stack gets filled.

#include<stdio.h>
#include<stdlib.h>
#include<memory.h>
typedef struct ArrayStack
{
int top;
int capacity;
int *arr;
}*stack;

stack Creation()
{
 stack S;
 S=(stack)malloc(sizeof(struct ArrayStack));
 if(!S)return NULL;
 S->top=-1;
 S->capacity=1;
 S->arr=(int*)malloc(S->capacity*sizeof(int));
 if(!S->arr)return NULL;
 return S;
}
int is_Full(stack S)
{
return S->top==S->capacity-1;
}
int is_Empty(stack S)
{
return S->top==-1;
}

void Doubling(stack S)
{
 S->capacity*=2;
 S->arr=realloc(S->arr,S->capacity);
}

void push(stack S,int data)
{
if(is_Full(S)) 
Doubling(S);

S->arr[++S->top]=data;
}

int pop(stack S)
{
if(is_Empty(S))
printf("\nStack underflow");
else
return S->arr[S->top--];
}

int main()
{
stack S;
int i=0,size=9;
S=Creation();
**for(i=0;i<size;i++)
push(S,19+1);**   // As in this case

return 0;
}

Answer 1

S->arr = malloc(S->capacity * sizeof(int));
S->arr = realloc(S->arr, S->capacity);

You only reallocate enough space for S->capacity / sizeof(int) items.