Data structures - ISC Class 12 Computer Science Questions with Answers, Page 2

Recycle is an entity which can hold at the most 100 integers. The chain enables the user to add and remove integers from both the ends i.e. front and rear. Define a class ReCycle with the following details: Class name : ReCycle Data members/instance variables: ele[ ] : the array to hold the integer elements cap : stores the maximum capacity of the array front : to point the index of the front rear : to point the index of the rear Methods / Member functions: ReCycle (int max) : constructor to initialize the data cap = max, front = rear = 0 and to create the integer array. void pushfront(int v) : to add integers from the front index if possible else display the message(“full from front”). int popfront( ) : to remove the return elements from front. If array is empty then return-999. void pushrear(int v) : to add integers from the front index if possible else display the message(“full from rear”). int poprear( ) : to remove and return elements from rear. If the array is empty then return-999.

void pushfront(int v)
{
    if (front != 0)
        ele[front--] = v;
    else
        System.out.println("full from front");
}

int poprear()
{
    if (front != rear)
        return ele[rear--];
    else
        return -999;
}

At Get It All supermarket, a POS (Point of Sale) system is designed. The cart management is visible to the POS operator. The newer carts get added and once the bill payment is done the current cart gets checked out from the system. The operator has 4 options like add cart, check out cart, view cart queue and close the counter. The class Cart is created to represent the node of the linked list.

public class Cart 
{ 
    int cartNo; 
    Cart next; 
    Cart(int cartNo) 
    { 
        this.cartNo = cartNo; 
        next = null; 
    } 
}

The class POS is created to represent the POS for cart management. Observe the given code and answer the following questions.

import java.util.*; 
public class POS 
{ 
    Cart first; 
    static int count = 0; 
    static Scanner sc = new Scanner(System.in); 
    void viewQueue( ) 
    { 
        Cart temp = first; 
        boolean flag = false; 
        System.out.println("The carts at the counter are"); 
        while(temp != null)  
        {        
            System.out.println(temp.cartNo); 
            ?1? 
            ?2? 
        }  
        if(!flag) 
            System.out.println("The checkout counter is empty"); 
        else 
            System.out.println("number of carts currently=" + count); 
    } 
    void addCart()  
    { 
        System.out.print("Enter the new cart number: "); 
        int no = sc.nextInt(); 
        Cart newCart = new Cart(no); 
        if(first == null) 
            first = newCart; 
        else 
        { 
            Cart temp = first; 
            while(temp.next != null) 
                temp = temp.next;   
            temp.next = newCart; 
        } 
        count++; 
    } 
    void checkOutCart()  
    { 
        ?1? 
        System.out.println("Cart being removed =" + temp.cartNo);  
        ?2? 
        temp.next = null; 
        temp = null; 
        ?3? 
        System.out.println("Carts remaining " + count); 
    } 
}

Shelf is a kind of data structure which can store elements with the restriction that an element can be added from the rear end and removed from the front end only. The details of the class Shelf are given below: Class name : Shelf Data members/instance variables: ele[ ] : array to hold decimal numbers lim : maximum limit of the shelf front : to point the index of the front end rear : to point the index of the rear end Methods / Member functions: Shelf(int n ) : constructor to initialize lim=n, front= 0 and rear=0 void pushVal(double v) : to push decimal numbers in the shelf at the rear end if possible, otherwise display the message “ SHELF IS FULL ” double popVal( ) : to remove and return the decimal number from the front end of the shelf if any, else returns −999.99 void display( ) : to display the elements of the shelf

void pushVal(double v)
{
    if (rear == lim)
        System.out.println("SHELF IS FULL");
    else
    {
        ele[rear] = v;
        rear++;
    }
}

double popVal()
{
    if (front == rear)
        return -999.99;
    else
    {
        double v = ele[front];
        front++;
        return v;
    }
}

Answer the following questions from the diagram of a Binary Tree given below:

CardGame is a game of mental skill, built on the simple premise of adding and removing the cards from the top of the card pile. The details of the class CardGame are given below.

Class name	:	CardGame
Data members/ instance variables:
cards[ ]	:	array to store integers as cards
cap	:	to store the maximum capacity of array
top	:	to store the index of the topmost element of the array
Methods / Member functions:
CardGame(int cc)	:	constructor to initialise cap=cc and top=-1
void addCard(int v)	:	to add the card at the top index if possible, otherwise display the message “CARD PILE IS FULL”
int drawCard()	:	to remove and return the card from the top index of the card pile, if any, else return the value -9999
void display( )	:	to display all the cards of card pile

void addCard(int v)
{
    if (top == cap - 1)
        System.out.println("CARD PILE IS FULL");
    else
    {
        top++;
        cards[top] = v;
    }
}

int drawCard()
{
    if (top == -1)
        return -9999;
    int val = cards[top];
    top--;
    return val;
}

Answer the following questions from the diagram of a Binary Tree given below: