Implementation_of_Stack

#define stacksize 5
#include<stdio.h>
struct stack
{
	int items[stacksize];
	int top;
};
typedef struct stack STACK;
void push(STACK *s,int ele)
{
	if(s->top==stacksize-1)
	{
		printf("Stack is full");
	    exit(0);
	}
	else
	s->items[++s->top]=ele;
}
int stackempty(STACK *s)
{
	return(s->top==-1);
}
void pop(STACK *s,int *ele,int *flag)
{
	*flag=0;
	if(stackempty(s))
	{
		printf("Stack is empty\n");
		*flag=1;
	}
	else
	*ele=s->items[s->top--];
}
void display(STACK s)
{
	int i;
	for(i=0;i<=s.top;i++)
	{
	printf("\n%d\n",s.items[i]);
}
}
void main()
{
	STACK s;
	int choice,uflag,ele;
	s.top=-1;
	do{
		printf("1.PUSH 2.POP 3.DISPLAY\n");
		scanf("%d", &choice);
		switch(choice)
		{
			case 1:printf("Enter the element to be pushed\n");
			scanf("%d",&ele);
			push(&s,ele);
			break;
			case 2:pop(&s,&ele,&uflag);
			if(uflag=0)
			printf("Popped=%d\n",ele);
			break;
			case 3:printf("The stack contains:");
			display(s);
			break;
			default:printf("Invalid choice\n");
			exit(0);	
		}
	}while(choice<=4);
}