ISC Class 12 Computer Science Board Exam Question Paper 2010 with Solutions

ISC Class 12 Computer Science Board Exam Question Paper with Solutions

Question 1
A bank intends to design a program to display the denomination of an input amount, up to 5 digits.
The available denomination with the bank are of rupees 1000 , 500 , 100 , 50 , 20 , 10 , 5 , 2 , and 1.
Design a program to accept the amount from the user and display the break-up in descending order of denomination. (i.e. preference should be given to the highest denomination available) along with the total number of notes. [Note: Only the denomination used should be displayed]. Also print the amount in words according to the digits.

Answer:

import java.util.Scanner;

public class Denomination
{
    public static void main(String args[])
    {
        Scanner sc = new Scanner(System.in);
        System.out.println("INPUT :");
        int amt = sc.nextInt();
        if(amt <= 0 || amt > 99999)
        {
            System.out.println("INVALID AMOUNT");
            return;
        }
        
        int temp = amt;
        String words = "";
        int rev = 0, count = 0;
        while(temp > 0)
        {
            rev = (rev * 10) + (temp % 10);
            temp /= 10;
            count++;
        }
        
        String w[] = {"ZERO", "ONE", "TWO", "THREE", "FOUR", "FIVE", "SIX", "SEVEN", "EIGHT", "NINE"};
        while(rev > 0)
        {
            int d = rev % 10;
            words = words + w[d] + " ";
            rev /= 10;
        }
        System.out.println("OUTPUT : " + words.trim());
        
        int denom[] = {1000, 500, 100, 50, 20, 10, 5, 2, 1};
        int totalNotes = 0;
        System.out.println("DENOMINATION :");
        for(int i = 0; i < denom.length; i++)
        {
            int n = amt / denom[i];
            if(n > 0)
            {
                System.out.println(denom[i] + " x " + n + " = " + (denom[i] * n));
                totalNotes += n;
                amt %= denom[i];
            }
        }
        System.out.println("TOTAL = " + temp);
        System.out.println("TOTAL NUMBER OF NOTES = " + totalNotes);
    }
}

Teacher's Note:
a) Use integer division and modulus operators to extract the exact count of each currency note starting from the highest denomination.
b) Ensure proper handling of numbers ending in zero while converting digits to words by reversing the number before extraction.

Question 2
A positive whole number 'n' that has 'd' number of digits is squared and split into two pieces, a right-hand piece that has 'd' digits and a left-hand piece that has remaining 'd' or 'd-1' digits. If the sum of the two pieces is equal to the number, then 'n' is a Kaprekar number. The first few Kaprekar numbers are: 9, 45, 297 ........
Given the two positive integers p and q, where p < q, write a program to determine how many Kaprekar numbers are there in the range between p and q (both inclusive) and output them.
The input contains two positive integers p and q. Assume p < 5000 and q < 5000. You are to output the number of Kaprekar numbers in the specified range along with their values in the format specified below:

Answer:

import java.util.Scanner;

public class KaprekarRange
{
    public static void main(String args[])
    {
        Scanner sc = new Scanner(System.in);
        System.out.println("INPUT:");
        System.out.print("p = ");
        int p = sc.nextInt();
        System.out.print("q = ");
        int q = sc.nextInt();
        
        int count = 0;
        String res = "";
        
        for(int i = p; i <= q; i++)
        {
            int temp = i;
            int digits = 0;
            while(temp > 0)
            {
                digits++;
                temp /= 10;
            }
            
            long sq = (long)i * i;
            long divisor = (long)Math.pow(10, digits);
            long right = sq % divisor;
            long left = sq / divisor;
            
            if(left + right == i)
            {
                if(count == 0)
                    res = res + i;
                else
                    res = res + ", " + i;
                count++;
            }
        }
        
        System.out.println("OUTPUT:");
        System.out.println("THE KAPREKAR NUMBERS ARE:-");
        System.out.println(res);
        System.out.println("FREQUENCY OF KAPREKAR NUMBERS IS: " + count);
    }
}

Teacher's Note:
a) Calculate the number of digits in the given number to determine the proper power of 10 for splitting the squared value.
b) Use long data type for storing squares to prevent integer overflow for larger numbers.

Question 3
Input a paragraph containing 'n' number of sentences where (1 = < n < 4). The words are to be separated with a single blank space and are in UPPERCASE. A sentence may be terminated either with a full stop '.' or a question mark '?' only. Any other character may be ignored. Perform the following operations:
i. Accept the number of sentences. If the number of sentences exceeds the limit, an appropriate error message must be displayed.
ii. Find the number of words in the whole paragraph
iii. Display the words in ascending order of their frequency. Words with same frequency may appear in any order.

Answer:

import java.util.Scanner;

public class ParagraphProcessor
{
    public static void main(String args[])
    {
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter number of sentences.");
        int n = sc.nextInt();
        sc.nextLine();
        if(n < 1 || n >= 4)
        {
            System.out.println("Invalid entry");
            return;
        }
        
        System.out.println("Enter sentences.");
        String para = sc.nextLine();
        
        String clean = "";
        for(int i = 0; i < para.length(); i++)
        {
            char ch = para.charAt(i);
            if(Character.isLetter(ch) || ch == ' ')
            {
                clean += ch;
            }
            else if(ch == '.' || ch == '?')
            {
                clean += " ";
            }
        }
        
        String words[] = clean.trim().split("\\s+");
        if(words.length == 1 && words[0].equals(""))
        {
            System.out.println("Total number of words: 0");
            return;
        }
        
        System.out.println("Total number of words: " + words.length);
        
        String unique[] = new String[words.length];
        int freq[] = new int[words.length];
        int uCount = 0;
        
        for(int i = 0; i < words.length; i++)
        {
            int index = -1;
            for(int j = 0; j < uCount; j++)
            {
                if(unique[j].equals(words[i]))
                {
                    index = j;
                    break;
                }
            }
            if(index == -1)
            {
                unique[uCount] = words[i];
                freq[uCount] = 1;
                uCount++;
            }
            else
        {
                freq[index]++;
            }
        }
        
        for(int i = 0; i < uCount - 1; i++)
        {
            for(int j = i + 1; j < uCount; j++)
            {
                if(freq[i] > freq[j])
                {
                    int tf = freq[i];
                    freq[i] = freq[j];
                    freq[j] = tf;
                    
                    String tw = unique[i];
                    unique[i] = unique[j];
                    unique[j] = tw;
                }
            }
        }
        
        System.out.println("WORD\t\tFREQUENCY");
        for(int i = 0; i < uCount; i++)
        {
            System.out.println(unique[i] + "\t\t" + freq[i]);
        }
    }
}

Teacher's Note:
a) Filter out non-alphabetic characters and sentence terminators while extracting individual words correctly.
b) Sort the unique words based on their frequencies in ascending order using standard sorting techniques like Bubble Sort.