Answer to Question #194959 in C++ for haseena

Question

Create a library management system in which you have a pile of 4 books stacked over one another. Each book has a book number. Make a program in which a librarian stacks a pile of books over one another. A student wants to issue a book. The program first searches if the book is present in the stack or not. If the book has not been issued, the program finds out the index of the book. It also pops other books on the top of it to issue the book to the student. Display the books in the stack. (Hint: report the count of the books above the required book and use the pop() function “count” times.)

Answer 1

#include <iostream>
using namespace std;
class Library{
    int *books;
    int size;
    public:
    Library(){
        size = 4;
        books = new int[size];
        for(int i = 0; i < 4; i++) books[i] = i + 1;
    }
    bool find(int n){
        for(int i = 0; i < size; i++) if(books[i] == n) return true;
        cout<<"\nBook "<<n<<" not found\n";
        return false;
    }
    void pop(int n){
        if(find(n)){
            cout<<"\nBook found\n";
            int temp;
            for(int i = 0; i < size; i++){
                if(books[i] == n){
                    temp = books[i];
                    books[i] = books[size - 1];
                    books[size - 1] = temp;
                }
            }
            cout<<"\nBook "<<n<<" issued";
            books = (int*)realloc(books, (--size) * sizeof(int));
        }
    }
    void display(){
        cout<<"\nBooks present\n";
        for(int i = 0; i < size; i++) cout<<books[i]<<endl;
    }
};
int main(){
    Library library;
    library.display();
    library.pop(1);
    library.display();
    library.pop(1);


    return 0;
}