Write a Program in Java to input a number and check whether it is a Pronic Number or Heteromecic Number or not.

Pronic Number : A Pronic number, oblong number, rectangular number or Heteromecic number, is a number which is the product of two consecutive integers, that is, n (n + 1).

The first few Pronic numbers are:
0, 2, 6, 12, 20, 30, 42, 56, 72, 90, 110, 132, 156, 182, 210, 240, 272, 306, 342, 380, 420, 462 … etc.
Code-1: Using Pure Function ( Return):

import java.util.*;
class Pronic_Number
{
public int func ( int n )
{
   int i,f=0;
    for( i=1; i<=n; i++)
    {
      if ( i * ( i + 1 ) ==n )
      {
        f=1;
        break;
      }
    }
return f;
}
public static void main ( String args [ ] )
{
   int no, p;
   Scanner sc=new Scanner(System.in);
   System.out.println("Enter the number: ");
   no=sc.nextInt();
   Pronic_Number obj = new Pronic_Number( );
    p=obj.func(no);
    if(p==1)
    {
     System.out.println(no + " is a Pronic Number");
    }
      else
        System.out.println(no + " is not a Pronic Number");
  }
}

Output:

Enter a number : 20
20 is a Pronic Number.

Enter a number : 73
73 is not a Pronic Number.