Untitled

#include<stdio.h>
int stack[100],i,j,choice=0,n,top=-1;
void push();
void pop();
void show();
void exit();
void main()
{
    printf("***********Stack operations using array **********");
        printf("\n.................+++++++++++..............\n");
        printf("\n Enter the size of stack :  ");
        scanf("%d",&n);
        while(choice!=4)
        {
            printf("Choose one from the below options+++ : \n ");
            printf("\n 1.push \n 2.pop \n 3.Show \n 4.Exit");
            printf("\n Enter  your Choice : \n ");
            scanf("%d",&choice);
            switch(choice)
            {
            case 1:
                {
                    push();
                    break;
                }
            case 2:
                {
                    pop();
                    break;
                }
                case 3:
                {
                    show();
                    break;
                }
                case 4:
                    {
                        exit();
                        printf("\n Exiting....\n");
                        break;
                    }
                default:
                    {
                        printf("Please Enter  from 1 to 4");
                    }
            };
        }
}

void push()
{
   int val;
   if(top==n-1)
        printf("\n Overflow");
   else
   {
       printf("Enter The Value?");
       scanf("%d",&val);
       top=top+1;
       stack[top]=val;
   }
}
void pop()

{
if(top==-1)
    printf("Underflow\n");
else
    top=top-1;



}

void show()
{
for(i=top;i>=0;i--)
{
    printf("%d\n",stack[i]);

}
if(top==-1)
{
    printf("Stack is Empty\n");
}
}