Computer Science (Theory) Official Board 2024-2025 ISC (Commerce) Class 12 Question Paper Solution

The complement of the Boolean expression (A • B') + (B' • C) is ______.

Consider the following code statement:

public class Person
{ int age;
  public Person (int age)
   {
    this.age = age;
   }
}

Which of the following statements are valid for the given code?

1. The keyword this in the constructor refers to the current instance of the class.
2. The keyword this differentiates between the instance variable age and the parameter age.
3. The keyword this can be used only in constructors.

Consider the following code statement:

public class Person
{ int age;
  public Person (int age)
   {
    this.age = age;
   }
}

Which of the following statements are valid for the given code?

1. The keyword this in the constructor refers to the current instance of the class.
2. The keyword this differentiates between the instance variable age and the parameter age.
3. The keyword this can be used only in constructors.

Assertion: If it is not a Sunday, then it is not a holiday. (Q' ⇒ P')

Reason: Inverse is formed when antecedent and consequent are interchanged.

For the given code segment, write Big O notation for worst case complexity.

for (int i=1; i<=P; i++)
 { Statements }
   for (int j=1; j<=P; ++j)
     for (int k=1; k<=Q; k++)
         { Statements }

Convert the following infix notation to postfix form.

A matrix M[–1...10, 4....13] is stored in the memory with each element requiring 2 bytes of storage. If the base address is 1200, find the address of M[2][7] when the matrix is stored Row Major Wise.

What is the function solve() performing apart from recursion?

The following function duck () is a part of some class which is used to check if a given number is a duck number or not. There are some places in the code marked by ?1?, ?2?, ?3? which may be replaced by a statement/expression so that the function works properly.

boolean duck(int a)
{ int f=−1;
  if(a==0)
    return true;
  for(int i=a; i!=0;?1?)
{ int c = i%10;
  if(c==?2?)
    { f=1; break; }
}
return (f==?3?)? false:true;
}

Reduce the above expression X (A, S, C, L) by using 4-variable Karnaugh map, showing the various groups (i.e., octal, quads and pairs). Draw the logic gate diagram using NOR gates only for the reduced expression. Assume that the variables and their complements are available as inputs.

Reduce the Boolean function F(P, Q, R, S) = ∑(0, 1, 2, 5, 7, 8, 9, 10, 13, 15) by using 4-variable Karnaugh map, showing the various groups (i.e., octal, quads and pairs).

Draw the logic gate diagram using NAND gates only for the reduced expression. Assume that the variables and their complements are available as inputs.

Draw the logic gate diagram for an octal to binary encoder.

By using truth table, verify if the following proposition is valid or not.

Study the logic gate diagram given below and answer the questions that follow:

What will be the output of the above gate when:

1. A = 1, B = 0  [1]
2. A = 1, B = 1  [1]

A class Flipgram has been defined to flip the letters of the left and right halves of a non-heterogram word. If the word has odd number of characters, then the middle letter remains at its own position.
A heterogram is a word where no letter appears more than once.

Example 1: INPUT : BETTER
                   OUTPUT: TERBET

Example 2: INPUT : NEVER
                   OUTPUT: ERVNE

Example 3: INPUT : THAN
                   OUTPUT: HETEROGRAM

The details of the members of the class are given belwo:

A linked list is formed from the objects of the class Cell. The class structure of the Cell is given below:

class Cell
{
    char m;
    Cell right;
}

Answer the following questions based on the Binary Tree given below:

1. Write the in-order traversal of the right subtree.  [1]
2. State the depth of the entire binary tree and depth of node E.  [1]
3. Name the external nodes of the left subtree and internal nodes of the right subtree.  [1]