JavaAlgorithms/Others/Armstrong.java
shellhub 2bd49e4728 * fix doc
* add test
* fix armstrong number
2020-08-12 22:04:20 +08:00

44 lines
1.3 KiB
Java

package Others;
/**
* An Armstrong number is equal to the sum of the cubes of its digits.
* For example, 370 is an Armstrong number because 3*3*3 + 7*7*7 + 0*0*0 = 370.
* An Armstrong number is often called Narcissistic number.
*/
public class Armstrong {
public static void main(String[] args) {
assert (isArmStrong(0));
assert (isArmStrong(1));
assert (isArmStrong(153));
assert (isArmStrong(1634));
assert (isArmStrong(371));
assert (!isArmStrong(200));
}
/**
* Checks whether a given number is an armstrong number or not.
*
* @param number number to check
* @return {@code true} if given number is armstrong number, {@code false} otherwise
*/
private static boolean isArmStrong(int number) {
int sum = 0;
int temp = number;
int numberOfDigits = 0;
while (temp != 0) {
numberOfDigits++;
temp /= 10;
}
temp = number; /* copy number again */
while (number > 0) {
int remainder = number % 10;
int power = 1;
for (int i = 1; i <= numberOfDigits; power *= remainder, ++i) ;
sum = sum + power;
number /= 10;
}
return sum == temp;
}
}