2 D Array To Store Only Composite Numbers - BlueJ Program

 A class Composite contains a two-dimensional array of order [m x n]. The maximum values possible for both ‘m’ and ‘n’ is 20. Design a class Composite to fill the array with the first (m x n) composite numbers in column wise. [Composite numbers are those which have more than two factors.]The details of the members of the class are given below:

Class name: Composite

Data members/instance variables :arr[ ] [ ] :integer array to store the composite numbers column wise

 m        :integer to store the number of rows 

n:integer to store the number of columns 

Member functions/methods:

Composite(int mm, int nn ):to initialize the size of the matrix, m=mm and n=nn

 int isComposite( int p ):to return 1 if the number is composite otherwise returns 0

void fill ( ):to fill the elements of the array with the first (m × n) composite numbers in column wise

void display( ):to display the array in a matrix form Specify     the     class Composite giving     details of     the constructor(int,int), int isComposite(int), void fill( ) and void display( ). Define a main( ) function to create an object and call all the functions accordingly to enable the task.

import java.util.*;
class Composite
{
int m,n,arr[][];
Scanner sc=new Scanner(System.in);
Composite(int mm, int nn)
{
    m=mm;
    n=nn;
    arr=new int [m][n];
}
private int isComposite( int p )
{
   int i;
   for(i=2;i<p;i++)
   {
        if(p%i==0)
        break;
   }
   if(i==p)
   return 0;
   else
   return 1;
}
private void display()
{
   int i,j;
   for(i=0;i<m;i++)
   {
        for(j=0;j<n;j++)
        {
            System.out.print(" "+arr[i][j]);
        }
        System.out.println();
   }
}
void fill ( )
{
    int i,j;
   for(i=0;i<m;i++)
   {
        for(j=0;j<n;j++)
        {
            System.out.print("\nEnter Number:");
            int d=sc.nextInt();
            if(isComposite(d)==1)
            arr[i][j]=d;
            else
            {
                System.out.print("\nEnter Composite Number "+d + "  is not composite");
                j--;
            }   
        }
    }
}
public static void main(String args[])
{
    int m,n;
    Scanner sc=new Scanner(System.in);
    while(true)
    {
        System.out.print("\nEnter Row Number:");
        m=sc.nextInt();
        if(m>0 && m<=20)
        break;
    }
    while(true)
    {
        System.out.print("\nEnter Column Number:");
        n=sc.nextInt();
        if(n>0 && n<=20)
        break;
    }
Composite ob=new Composite(m,n);
ob.fill();
System.out.print("\nFinal Matrix\n");
ob.display();
}
}