Question. Write a Java Program
to check Kaprekar number.
Kaprekar number are those
number whose square, if split into parts and then add it, will be the same as
the original number. It is named after Dattaraya Ramchandra Kaprekar was an Indian.
Say 45, If we square it we
get 2025 that is 452 = 2025, and split it as 20 and 25 then add it,
will get 45.
452 = 2025 then
20 + 25 = 45.
Java program as follows
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.IOException;
public class KaprekarNum{
// main method
begins execution of this class
public static void
main(String args[]) throws IOException
{
int square,
temp, counter = 0, reminder, quotient;
int n; // The number to find Kaprekar Number
InputStreamReader input = new InputStreamReader(System.in);
BufferedReader
br = new BufferedReader(input);
System.out.print("Enter a number to check Kaprekar number: ");
// Waiting for
the user input
n =
Integer.parseInt(br.readLine()); // say 45
temp = n; // Store n into temp variable
square = n *
n; // Square of 45 is 2025
// find total
number of digits
while (n != 0)
{
counter++;
n = n /
10;
}
// reminder
for 2025 % 100 will be 25
reminder =
square % ((int) Math.pow(10, counter));
// quotient
for 2025 / 100 will be 20
quotient =
square / ((int) Math.pow(10, counter));
/* checking the Kaprekar number after adding of reminder and quotient
with the original number */
if ((reminder
+ quotient) == temp)
{
System.out.println(temp + " is a kaprekar number ");
} else
{
System.out.println(temp + " is not a kaprekar number ");
}
} // end method
main
} // end class
Output
Enter a number to check Kaprekar number: 45
45 is a kaprekar number
Enter a number to check Kaprekar number: 44
44 is not a kaprekar number
