ISC Class 12 Computer Science previous year paper (2018)

Design a class EqMat to check if two matrices are equal or not. Assume that the two
matrices have the same dimension.
Some of the members of the class are given below:

Class name	EqMat
Data members/instance variables:
a[ ][ ]	to store integer elements
m	to store the number of rows
n	to store the number of columns
Member functions/methods:
EqMat(int mm, int nn)	parameterised constructor to initialise the data members m = mm and n = nn
void readarray( )	to enter elements in the array
int check(EqMat P, EqMat Q)	checks if the parameterized objects P and Q are equal and returns 1 if true, otherwise returns 0
void print( )	displays the array elements

Define the class EqMat giving details of the constructor( ), void readarray( ), int check(EqMat, EqMat) and void print( ). Define the main( ) function to create objects and call the functions accordingly to enable the task.

import java.util.*;
class EqMat
{
   int a[][];
   int m;
   int n;
   static Scanner sc=new Scanner(System.in);
   EqMat(int mm,int nn)
   { 
       m=mm;
       n=nn;
       a=new int[m][n];
   }
   void readarray()
   { 
      System.out.println("enter" + (m*n) + "elements" );
      for (int i=0;i<m;i++)
         for (int j=0;j<n;j++)
            a[i][j]=sc.nextInt();
   }
   int check(EqMat P,EqMat Q)
   { 
      for (int i=0;i<P.m;i++)
         for (int j=0;j<P.n;j++)
         { 
            if (P.a[i][j]!=Q.a[i][j])
               return 0;
         }
         return 1;
   }
   void print()
   { 
       for (int i=0;i<m;i++)
       { 
          System.out.println();
          for (int j=0;j<n;j++)
             System.out.print(a[i][j]+"\t");
       }
   }
   public static void main()
   { 
      EqMat ob1=new EqMat(3,3);
      EqMat ob2=new EqMat(3,3);
      System.out.println("enter nos for the Ist Matrix");
      ob1.readarray();
      System.out.println("enter nos for the 2nd Matrix");
      ob2.readarray();
      if (ob1.check(ob1,ob2)==1)
      { 
         System.out.println("Equal Matrix");
         ob1.print();
         ob2.print();
      }
      else
         System.out.println("not equal");
   }
}

Question 9 [marks 10]

A class Capital has been defined to check whether a sentence has words beginning with a capital letter or not.
Some of the members of the class are given below:

Class name	Capital
Data member/instance variable:
sent	to store a sentence
freq	stores the frequency of words beginning with a capital letter
Member functions/methods:
Capital( )	default constructor
void input()	to accept the sentence
boolean isCap(String w)	checks and returns true if word begins with a capital letter, otherwise returns false
void display ()	displays the sentence along with the frequency of the words beginning with a capital letter

Specify the class Capital, giving the details of the constructor( ), void input( ), boolean isCap(String) and void display( ). Define the main( ) function to create an object and call the functions accordingly to enable the task.

import java.util.*;
class Capital
{
   String sent;
   int freq;
   Capital()
   {
     sent="";
     freq=0;
   }
   void input()
   {
      Scanner sc=new Scanner(System.in);
      System.out.println("Enter the sentence");
      sent=sc.nextLine();
   }
   boolean isCap(String w)
   {
       char c=w.charAt(0);
       if (Character.isUpperCase(c) )
         return true;
       else
         return false;
   }
   void display()
   { 
      System.out.println("sentence="+sent);
      String b=" "+sent;
      char c;
      for(int i=0;i<b.length();i++)
      { 
         c=b.charAt(i);
         if (c==' ')
         { 
            if(Character.isUpperCase(b.charAt(i+1)) )
               freq++;
         }
      }
      System.out.println("Freqency of title word="+freq);
   }
   public static void main()
   {
      Capital ob=new Capital();
      ob.input();
      ob.display();
   }
}

SECTION – C
Answer any two questions.

Question 10 [marks 5]

A super class Number is defined to calculate the factorial of a number. Define a sub class Series to find the sum of the series S = 1! + 2! + 3! + 4!+……………+n!
The details of the members of both the classes are given below:

Class name	Number
Data member/instance variable:
n	to store an integer number
Member functions/methods:
Number(int nn)	parameterized constructor to initialize the data member n=nn
int factorial (int a)	returns the factorial of a number (factorial of n = 1×2×3×………×n)
void display()	displays the data members
Class name:	Series
Data member/instance variable:
sum	to store the sum of the series
Member functions/methods:
Series(…)	parameterized constructor to initialize the data members of both the classes
void calsum( )	calculates the sum of the given series
void display( )	displays the data members of both the classes

Assume that the super class Number has been defined. Using the concept of inheritance, specify the class Series giving the details of the constructor(…),void calsum( ) and void display( ).
The super class, main function and algorithm need NOT be written.

class Series extends Number
{
   long sum;
   Series(int nn)
   {
      super(nn);
      sum=0;
   }
   void calsum() 
   { 
      for (int i=1;i<=n;i++) 
        sum=sum+factorial(i);
   } 
   void display()
   {
       super.display();
       System.out.println("sum of the series="+sum);
   }
}

Question 11 [marks 5]

Register is an entity which can hold a maximum of 100 names. The register enables the user to add and remove names from the top most end only.
Define a class Register with the following details:

Class name	Queue
Data Members / instance variables:
Que[ ]	array to hold the integer elements
size	stores the size of the array
front	to point the index of the front
rear	to point the index of the rear
Member functions:
Queue (int mm)	constructor to initialize the data size = mm, front = 0, rear = 0
void addele(int v )	to add integer from the rear if possible else display the message “Overflow”
int delele( )	returns elements from front if present, otherwise displays the message “Underflow” and return -9999
void display ( )	displays the array elements

(a) Specify the class Register giving details of the functions void push(String) and String pop( ). Assume that the other functions have been defined.
       The main function and algorithm need NOT be written.  [4]
(b) Name the entity used in the above data structure arrangement. [1]
Ans.

(a) 
class Register
{
   void push(String n)
   {
      if (top<cap-1)
        stud[++top]=n;
      else
        System.out.println("OVERFLOW");
   }
   String pop()
   { 
      if (top>=0)
        return stud[top--];
      else
        return " $";
   }
}

(b) The entity used in the above data structure is Stack.

Question 12

(a) A linked list is formed from the objects of the class Node. The class structure of the Node is given below: [2]

class Node
{
  int n;
  Node link;
}

Write an Algorithm OR a Method to search for a number from an existing linked list. The method declaration is as follows:
         void FindNode( Node str, int b )
(b) Answer the following questions from the diagram of a Binary Tree given below: