/**
* 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 com.thealgorithms.maths;
public final class DudeneyNumber {
private DudeneyNumber() {
}
// returns True if the number is a Dudeney number and False if it is not a Dudeney number.
public static boolean isDudeney(final int n) {
if (n <= 0) {
throw new IllegalArgumentException("Input must me positive.");
}
// Calculating Cube Root
final int cubeRoot = (int) Math.round(Math.pow(n, 1.0 / 3.0));
// If the number is not a perfect cube the method returns false.
if (cubeRoot * cubeRoot * cubeRoot != n) {
return false;
}
// If the cube root of the number is not equal to the sum of its digits, we return false.
return cubeRoot == SumOfDigits.sumOfDigits(n);
}
}