program3

#include<stdio.h>
	#include<stdlib.h>
	#include<string.h>
	#define SIZE 5
	
	
	struct BOOK{
		int ISBN;
		char title[20];
		char author[20];
		float price;
		};

	struct stack{
		struct BOOK b[SIZE];
		int top;
		};

	void push(struct stack *ps, struct BOOK b1);
	struct BOOK pop(struct stack *ps);
	void display(struct stack *ps);
	
	void main()
	{
		struct stack s;
		struct BOOK b1,r1;
		int choice;
		s.top=-1;
		do{
			printf("\n 1:PUSH\t 2:POP\t 3:DISPLAY\t 4:QUIT");
			printf("\n Enter your choice:");
			scanf("%d",&choice);
			switch(choice)
			{
				case 1:	 printf("Enter the ISBN, title, author and price of the book to push:");
					scanf("%d %s %s %f, ",&b1.ISBN, b1.title, b1.author, &b1.price);
					push(&s,b1);
					break;
				case 2: r1=pop(&s);
					printf("The details of BOOK popped is :");
					printf("\n ISBN =%d,  Title=%s, Author=%s, Price=%f", b1.ISBN, b1.title, b1.author, b1.price);					break;
				case 3: display(&s);
					break;
					printf("\n Stack empty");
				case 4 :printf("\nQuitting operation stack\n");	
					break;
				default :printf("No such option\n");
					break;
			}
			}while(choice !=4);
	}


	void push(struct stack *ps, struct BOOK b1)
	{
		if(ps->top==SIZE-1)
			printf("Stack Overflow\n");
		else {
			++(ps->top);
			ps->b[ps->top].ISBN=b1.ISBN;
			strcpy(ps->b[ps->top].title, b1.title);
			strcpy(ps->b[ps->top].author, b1.author);
			ps->b[ps->top].price=b1.price;
		}
	}
	
	struct BOOK pop(struct stack *ps)
	{
		struct BOOK r;
		if(ps->top==-1)
		{
			printf("\n Stack Underflow");
			exit(1);
		}
		r.ISBN=ps->b[ps->top].ISBN;
		strcpy(r.title, ps->b[ps->top].title);
		strcpy(r.author, ps->b[ps->top].author);
		r.price=ps->b[ps->top].price; 
		(ps->top)--;
		return(r);
	}	


	void display(struct stack *ps)
	{
	int i;
	if(ps->top==-1)
		printf("\n Stack is empty");
	else
	{
		printf("Stack contents are:\n");
		for(i=ps->top;i>=0;i--)
		{
			printf("\n ISBN= %d   Title=%s  Author=%s   Price=%f", ps->b[i].ISBN, ps->b[i].title, ps->b[i].author, ps->b[i].price);
		}
	}
}