Add Dudeney Number (#2629)

Maths/DudeneyNumber.java

@@ -0,0 +1,65 @@
+/**
+ * A number is said to be Dudeney if the sum of the digits, is the cube root of the entered number.
+ * Example- Let the number be 512, its sum of digits is 5+1+2=8. The cube root of 512 is also 8.
+ *          Since, the sum of the digits is equal to the cube root of the entered number;
+ *          it is a Dudeney Number.
+ */
+package Maths;
+
+import java.io.*;
+
+
+public class DudeneyNumber
+{
+    //returns True if the number is a Dudeney number and False if it is not a Dudeney number.
+    public static boolean isDudeney(int n)
+    {
+        // Calculating Cube Root
+        int cube_root = (int)(Math.round((Math.pow(n, 1.0 / 3.0))));
+        // If the number is not a perfect cube the method returns false.
+        if (cube_root * cube_root * cube_root != n)
+            return false;    
+        int sum_of_digits = 0;// Stores the sums of the digit of the entered number
+        int temp = n;//A temporary variable to store the entered number
+        // Loop to calculate sum of the digits.
+        while (temp > 0)
+        {
+
+            // Extracting Last digit of the number
+            int rem = temp % 10;
+
+            // Calculating sum of digits.
+            sum_of_digits += rem;
+
+            // Removing the last digit
+            temp /= 10;
+        }
+
+        //If the cube root of the number is not equal to the sum of its digits we return false.  
+        if (cube_root != sum_of_digits)
+            return false;
+
+        return true;
+    }
+
+    /** Method to check if number is Dudeney Number or Not
+     *  1) Input  - Enter a Number: 512
+     *     Output - It is a Dudeney Number.
+     *  2) Input  - Enter a Number: 125
+     *     Output - It is not a Dudeney Number.
+     */
+    public static void main(String args[]) throws IOException
+    {
+        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
+        System.out.println("Enter a Number: ");
+        int n=Integer.parseInt(br.readLine());
+        if(isDudeney(n))
+        {
+            System.out.println("It is a Dudeney Number.");
+        }
+        else
+        {
+            System.out.println("It is not a Dudeney Number.");
+        }
+    }
+}