Add Kaprekar Number Detector

KaprekarNumber.java

@@ -0,0 +1,52 @@
+import java.util.Scanner;
+
+/*
+ * A Kaprekar number is a number whose square when divided into two parts
+ * and such that sum of parts is equal to the original number and none of the parts has value 0.
+ * For example, 45 is a Kaprekar number, because 45^2 = 2025 and 20 + 25 = 45.
+ */
+public class KaprekarNumber {
+    public static void main(String[] args) {
+        // Initialize the scanner class to take input
+        Scanner sc = new Scanner(System.in);
+
+        // Prompt the user for input
+        System.out.print("Enter number to check if it is Kaprekar or not : ");
+
+        // Take input
+        int num = sc.nextInt();
+
+        // Check if number is Kaprekar and print the desired message
+        if (checkKaprekar(num))
+            System.out.println("This number is an Kaprekar Number");
+        else
+            System.out.println("This number is not an Kaprekar Number");
+    }
+
+    public static boolean checkKaprekar(int number){
+        // 1. Find square of number
+        int square = number * number;
+
+        // 2. Count number of digits in square
+        int count = 0;
+
+        // 3. Find sum of digits from right side
+        while (square != 0){
+            count++;
+            square /= 10;
+        }
+
+        // 4. Find sum of digits from left side
+        square = number * number;
+
+        // 5. Check if sum of digits is equal to original number
+        for (int i = 1; i < count; i++){
+            int first = (int) (square / Math.pow(10, i));
+            int second = (int) (square % Math.pow(10, i));
+            if (first + second == number && first != 0 && second != 0){
+                return true;
+            }
+        }
+        return false;
+    }
+}