Solved 2018 Practical Paper ISC Computer Science

A Goldbach number is a positive even integer that can be expressed as the sum of two odd primes.

Note: All even integer numbers greater than 4 are Goldbach numbers.

Example:

6 = 3 + 3
10 = 3 + 7
10 = 5 + 5

Hence, 6 has one odd prime pair 3 and 3. Similarly, 10 has two odd prime pairs, i.e. 3 and 7, 5 and 5.

Write a program to accept an even integer 'N' where N > 9 and N < 50. Find all the odd prime pairs whose sum is equal to the number 'N'.

Test your program with the following data and some random data:

Example 1

INPUT:
N = 14

OUTPUT:
PRIME PAIRS ARE:
3, 11
7, 7

Example 2

INPUT:
N = 30

OUTPUT:
PRIME PAIRS ARE:
7, 23
11, 19
13, 17

Example 3

INPUT:
N = 17

OUTPUT:
INVALID INPUT. NUMBER IS ODD.

Example 4

INPUT:
N = 126

OUTPUT:
INVALID INPUT. NUMBER OUT OF RANGE.

import java.util.Scanner;

public class GoldbachNumber
{
    public static boolean isPrime(int num) {
        int c = 0;
        
        for (int i = 1; i <= num; i++) {
            if (num % i == 0) {
                c++;
            }
        }
        
        return c == 2;
    }
    
    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        System.out.print("ENTER THE VALUE OF N: ");
        int n = in.nextInt();
        
        if (n <= 9 || n >= 50) {
            System.out.println("INVALID INPUT. NUMBER OUT OF RANGE.");
            return;
        }
        
        if (n % 2 != 0) {
            System.out.println("INVALID INPUT. NUMBER IS ODD.");
            return;
        }
        
        System.out.println("PRIME PAIRS ARE:");
        
        int a = 3;
        int b = 0;
        while (a <= n / 2) {
            b = n - a;
            
            if (isPrime(a) && isPrime(b)) {
                System.out.println(a + ", " + b);
            }
            
            a += 2;
        }
    }
}

Write a program to declare a matrix a[][] of order (m × n) where 'm' is the number of rows and 'n' is the number of columns such that the values of both 'm' and 'n' must be greater than 2 and less than 10. Allow the user to input integers into this matrix. Perform the following tasks on the matrix:

Test your program for the following data and some random data:

Example 1

INPUT:
M = 4
N = 3

ENTER ELEMENTS OF MATRIX:

$$\begin{matrix} 11 & -2 & 3 \\ 5 & 16 & 7 \\ 9 & 0 & 4 \\ 3 & 1 & 8 \end{matrix}$$

OUTPUT:
ORIGINAL MATRIX

$$\begin{matrix} 11 & -2 & 3 \\ 5 & 16 & 7 \\ 9 & 0 & 4 \\ 3 & 1 & 8 \end{matrix}$$

MATRIX AFTER SORTING ROWS

$$\begin{matrix} -2 & 3 & 11 \\ 5 & 7 & 16 \\ 0 & 4 & 9 \\ 1 & 3 & 8 \end{matrix}$$

Example 2

INPUT:
M = 3
N = 3

ENTER ELEMENTS OF MATRIX

$$\begin{matrix} 22 & 5 & 19 \\ 7 & 36 & 12 \\ 9 & 13 & 6 \end{matrix}$$

OUTPUT:
ORIGINAL MATRIX

$$\begin{matrix} 22 & 5 & 19 \\ 7 & 36 & 12 \\ 9 & 13 & 6 \end{matrix}$$

MATRIX AFTER SORTING ROWS

$$\begin{matrix} 5 & 19 & 22 \\ 7 & 12 & 36 \\ 6 & 9 & 13 \end{matrix}$$

Example 3

INPUT:
M = 11
N = 5

OUTPUT:
MATRIX SIZE OUT OF RANGE.

import java.util.Scanner;

public class ArraySort
{
    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        System.out.print("ENTER THE VALUE OF M: ");
        int m = in.nextInt();
        System.out.print("ENTER THE VALUE OF N: ");
        int n = in.nextInt();

        if (m <= 2 
        || m >= 10 
        || n <= 2 
        || n >= 10) {
            System.out.println("MATRIX SIZE OUT OF RANGE.");
            return;
        }

        int a[][] = new int[m][n];
        System.out.println("ENTER ELEMENTS OF MATRIX:");
        for (int i = 0; i < m; i++) {
            System.out.println("ENTER ELEMENTS OF ROW " + (i+1) + ":");
            for (int j = 0; j < n; j++) {
                a[i][j] = in.nextInt();
            }
        }

        System.out.println("ORIGINAL MATRIX");
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                System.out.print(a[i][j] + " ");
            }
            System.out.println();
        }

        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n - 1; j++) {
                for (int k = 0; k < n - j - 1; k++) {
                    if (a[i][k] > a[i][k + 1]) {
                        int t = a[i][k];
                        a[i][k] = a[i][k+1];
                        a[i][k+1] = t;
                    }
                } 
            }
        }
        
        System.out.println("MATRIX AFTER SORTING ROWS");
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                System.out.print(a[i][j] + " ");
            }
            System.out.println();
        }
    }
}

The names of the teams participating in a competition should be displayed on a banner vertically, to accommodate as many teams as possible in a single banner. Design a program to accept the names of N teams, where 2 < N < 9 and display them in vertical order, side by side with a horizontal tab (i.e. eight spaces).

Test your program for the following data and some random data:

Example 1

INPUT:
N = 3
Team 1: Emus
Team 2: Road Rols
Team 3: Coyote

OUTPUT:
E        R       C
m       o       o
u        a        y
s        d        o
                    t
          R        e
          o        
          l        
          s        

Example 2

INPUT:
N = 4
Team 1: Royal
Team 2: Mars
Team 3: De Rose
Team 4: Kings

OUTPUT:
R        M       D       K
o        a         e       i
y        r                  n
a        s          R      g
l                     o      s
                      s      
                      e      

Example 3

INPUT:
N = 10

OUTPUT:
INVALID INPUT

import java.util.Scanner;

public class Banner
{
    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        System.out.print("ENTER THE VALUE OF N: ");
        int n = in.nextInt();
        in.nextLine();
        
        if (n <= 2 || n >= 9) {
            System.out.println("INVALID INPUT");
            return;
        }
        
        String teams[] = new String[n];
        int highLen = 0;
        
        for (int i = 0; i < n; i++) {
             System.out.print("Team " + (i+1) + ": ");
             teams[i] = in.nextLine();
             if (teams[i].length() > highLen) {
                 highLen = teams[i].length();
             }
        }
        
        for (int i = 0; i < highLen; i++) {
            for (int j = 0; j < n; j++) {
                int len = teams[j].length();
                if (i >= len) {
                    System.out.print(" \t");
                }
                else {
                    System.out.print(teams[j].charAt(i) + "\t");
                }
            }
            System.out.println();
        }
    }
}