An Efficient Kaprekar Number

It is a number whose square, when divided into two parts, the sum of parts is equal to the original number
For Example 45–>(45)^2= 2025–>Now when we divide this number into two parts(20 and 25), their sum is 20+25=45. So It is a kaprekar number.

For string programs click the given link
https://java4school.com/string-programs-part-5

Write a program to accept a number and check whether it is a kaprekar number or not.

import java.io.*; 
class karpekar //sum of digits in its square is the number itself e.g., 45 
{ 
public static void main()throws IOException 
{ 
    BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); 
    System.out.println("Enter a number"); 
    int num=Integer.parseInt(br.readLine()); 
    int n=num; 
    int sq=num*num; 
    int count=0; 
    while(n!=0) 
    { 
      n=n/10; 
      count++; 
     } 
     int sq1=(int)(sq/Math.pow(10,count)); 
     int sq2=(int)(sq%Math.pow(10,count)); 
     if(sq1+sq2==num) 
     { 
        System.out.println("It is a karpekar number"); 
     } 
     else 
     { 
        System.out.println("It is not a karpekar number"); 
      } 
   } 
} 

Output:
Enter a number
45
It is a karpekar number

For videos to learn java programming click the given link
https://youtu.be/TRm9r4gFTho