ISC COMPUTER PRACTICAL PAPER 2018 SOLVED

## COMPUTER SCIENCE PRACTICAL SOLVED QUESTIONS – ISC BOARD 2018

– MARCH 21, 2019

QUESTION -1

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.

SOLUTION :

import java.util.*;
public class Goldbach
{
boolean isPrime(int n)
{
if(n<=1)        //All numbers that are less than or equal to one are  non-prime
return false;

int i;
for(i=2;i<=n/2;i++)
{
if(n%i==0)  //If any number between 2 and n/2 divides n then n is non prime
return false;
}
/*If any return statement is encountered it terminates the function immediately
* therefore the control will come here only when the above return statements are not executed
* which can happen only when the number is a prime number.
*/
return true;
}

void print(int n)
{
int i, j;
for(i=2;i<=n;i++)
{
for(j=i;j<=n;j++)
{
//If i and j are both prime and i+j is equal to n then i and j will be printed
if(isPrime(i)&&isPrime(j)&&i+j==n)
System.out.println(i+”, “+j);
}
}
}
public static void main()
{
Scanner sc = new Scanner(System.in);
int n;
System.out.println(“Enter the limit: “);
n = sc.nextInt();
if(n%2==1)
{       //Checking for invalid input and terminating the program
System.out.println(“INVALID INPUT. NUMBER IS ODD.”);
System.exit(0);
}
if(n<=9||n>=50)
{       //Checking for 2nd invalid input and terminating the program
System.out.println(“INVALID INPUT. NUMBER OUT OF RANGE.”);
System.exit(0);
}
Goldbach ob = new Goldbach();       //Creating object
System.out.println(“Prime Pairs are: “);
ob.print(n);
}
}

——END—————————–*———————————–

QUESTION -2

Write a program to declare a matrix A[ ] [ ] of order (M xN) 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:
(a) Display the original matrix.
(b) Sort each row of the matrix in ascending order using any standard sorting technique.
(c) Display the changed matrix after sorting each row. Test your program for the following data and some random data:

Example 1:

INPUT:
M = 4
N = 3

Example 2:
INPUT:
M = 3
N =3

Example 3:
INPUT:
M = 11
N = 5

OUTPUT:

MATRIX SIZE OUT OF RANGE

SOLUTION:

import java.util.*;
public class ISC
{
void sort(int a[])      //Taking  single dimension array as parameter
{
int i, j, n = a.length, tmp;        //a.length gives the number of values in the 1D array
for(i=0;i
{
for(j=0;j
{
if(a[j]>a[j+1])
{
tmp = a[j];
a[j] = a[j+1];
a[j+1] = tmp;
}
}
}
}

void display(int a[][])     //Taking 2D array as parameter
{
int i, j;
for(i=0;i
{
for(j=0;j
{
System.out.print(a[i][j]+”\t”);
}
System.out.println();
}
}

void ISC(int a[][])
{       //As arrays are reference data types any changes made to the formal parameter in this function.
//Will be reflected in the original parameter.
int i, j;
for(i=0;i
{
sort(a[i]);     //Taking each row and passing each to sort function as a single dimension array
}
}

public static void main()
{
Scanner sc = new Scanner(System.in);
ISC obj = new ISC();
int a[][], m, n, i, j;
System.out.println(“Enter the number of rows: “);
m = sc.nextInt();       //Input the size
System.out.println(“Enter the number of columns: “);
n = sc.nextInt();
if(m<3||m>9||n<3||n>9)
{
System.out.println(“Matrix out of range”);
System.exit(0);     //Terminating the program
}
a = new int[m][n];      //Allocating memory
System.out.println(“Enter the values for the matrix: “);
for(i=0;i
{
for(j=0;j
{
a[i][j] = sc.nextInt();
}
}
System.out.println(“Original Matrix: “);
obj.display(a);     //Displaying array before sorting
obj.sort2D(a);      //Calling sort function
System.out.println(“Matrix after sorting rows: “);
obj.display(a);     //Display after sort function has executed
}
}

–END———————————*———————————–

QUESTION -3

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 3: Coyote

OUTPUT:

SOLUTION:
import java.util.*;
public class ISC2018
{
public static void main()
{
Scanner sc = new Scanner(System.in);
String ar[];
int n, i, j;
System.out.println(“Enter the number of names: “);
n = sc.nextInt();
ar = new String[n];
System.out.println(“Enter the names: “);
for(i=0;i
{
ar[i] = sc.nextLine();
}
int max = 0;

for(i=0;i
{
if(max
max = ar[i].length();       //Finding the length of the string
}
System.out.println(“OUTPUT:” );
for(i=0;i
{
for(j=0;j
{
/*character will be extracted only when i has a value less
* than the length of the string else only tabular space will be printed
*/
if(i
System.out.print(ar[j].charAt(i)+”\t”);
else
System.out.print(“\t”);
}
System.out.println();
}
}
}

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