stack using array

/****************************
*  Umang B Bhatt            *
*   bhatt.umang7@gmail.com  *
*****************************/

/**
 * program for stack using array
 */
#include<stdio.h>
#define SIZE 100


int peep(int a[], int top, int i)
{

 if( i < 0 && i>= top)
 {
  printf("This is invalid operation. Index out of range.");
 }

 else
 {
  return a[i];
 }
}

int push(int *a , int top, int ele)
{

 if(top >= SIZE)
 {
  printf("\nStack Overflow");
 }
 else

 {
  a[++top] = ele;
 }
 return top;
}

int pop(int *a,int *top)
{
 if((*top) >=0)
 {
  (*top) = (*top) -1 ;

  return  a[(*top)+1];
 }
 else
 {
  printf("Stack underflow\n");

  return 0;
 }
}
void change(int *a,int top, int index, int element)
{

 if(index < 0 || index > top)
 {
  printf("The index is out of range");
 }

 else
 {
  a[index] = element;
 }
}


void main()
{
// void push(int [] ,int ,int );
 int i= 0 ;

 int top = -1;
 int a[SIZE];

 int d = 1;
 int temp,temp1;

 do
 {
  printf("\n\nSelect any option");
  printf("\n1 Display stack");

  printf("\n2 push");
  printf("\n3 pop");
  printf("\n4 peep");

  printf("\n5 change");
  printf("\n6 exit\n");
  scanf("%d",&d);

  
  switch(d)
  {
   case 1:
    if(top>=0)
    {

     for(i = 0 ; i <= top ; i++ )
     {

      printf("\nelement at %d is %d" , i , peep(a,top,i));
     }
    }

    else
    {
     printf("\nThe stack is empty");
    }
    break;
   case 2:

    printf("Enter number you want to insert in the stack: ");
    scanf("%d",&temp);
    top = push( a , top , temp);

    break;
   case 3:
    printf("The popped element is: %d" , pop(a,&top));

    break;
   case 4:
    printf("At which position you want to peep ? ");
    scanf("%d",&temp);

    printf("Peeped element is: %d" , peep(a,top,temp) );
    break;

   case 5:
    printf("Enter the index at which you want to change: "); 
    scanf("%d",&temp);

    printf("Enter he actual element that you want to enter: ");
    scanf("%d",&temp1);
    change(a,top,temp,temp1);

    break;
   default:
    printf("Please enter a valid choice.");
    break;
    
  }
 }

 while(d != 6);
 // and yes, i think you will be able to writ getch here (on TC3)
  // i am on linux so that thing is not available here
}