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1 | 1 | package com.sbiswas001.twelveproject; |
2 | 2 |
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| 3 | +import java.util.Scanner; |
| 4 | + |
| 5 | +/** |
| 6 | + * Checks if a number is armstrong or not. |
| 7 | + * A number is armstrong if the sum of each |
| 8 | + * digit to the power number of digits is |
| 9 | + * equal to the number itself. |
| 10 | + * @author Sayan Biswas |
| 11 | + * @version 25.04.2022 |
| 12 | + */ |
3 | 13 | public class ArmstrongNumber { |
| 14 | + /** |
| 15 | + * Stores the number |
| 16 | + */ |
| 17 | + private int number; |
| 18 | + |
| 19 | + /** |
| 20 | + * Initializes instance variables |
| 21 | + */ |
| 22 | + private ArmstrongNumber() { |
| 23 | + number = 0; |
| 24 | + } |
| 25 | + |
| 26 | + /** |
| 27 | + * Inputs a number from user |
| 28 | + */ |
| 29 | + private void input() { |
| 30 | + Scanner sc = new Scanner(System.in); |
| 31 | + System.out.print("Enter number: "); |
| 32 | + number = Integer.parseInt(sc.nextLine()); |
| 33 | + } |
| 34 | + |
| 35 | + /** |
| 36 | + * Returns number of digits of a number |
| 37 | + * @param n Number to be checked |
| 38 | + * @return Number of digits |
| 39 | + */ |
| 40 | + private int numberOfDigits(int n) { |
| 41 | + return (int)Math.floor(Math.log10(n))+1; |
| 42 | + } |
| 43 | + |
| 44 | + /** |
| 45 | + * Checks if a number is armstrong or not. |
| 46 | + * A number is armstrong if the sum of each |
| 47 | + * digit to the power number of digits is |
| 48 | + * equal to the number itself. |
| 49 | + * @param a Number to be checked |
| 50 | + * @return true or false |
| 51 | + */ |
| 52 | + private boolean armstrongCheck(int a) { |
| 53 | + int sum = 0; |
| 54 | + while(a > 0) { |
| 55 | + sum += (int)Math.pow(a % 10, numberOfDigits(number)); |
| 56 | + a /= 10; |
| 57 | + } |
| 58 | + return sum == number; |
| 59 | + } |
| 60 | + |
| 61 | + /** |
| 62 | + * Displays the result if number is armstrong or not |
| 63 | + */ |
| 64 | + private void display() { |
| 65 | + |
| 66 | + System.out.println(armstrongCheck(number) ? |
| 67 | + "Number is armstrong." : |
| 68 | + "Number is not armstrong."); |
| 69 | + } |
| 70 | + |
| 71 | + /** |
| 72 | + * Calls other methods |
| 73 | + * @param args Arguments passed to main method |
| 74 | + */ |
| 75 | + public static void main(String[] args) { |
| 76 | + ArmstrongNumber ob = new ArmstrongNumber(); |
| 77 | + ob.input(); |
| 78 | + ob.display(); |
| 79 | + } |
4 | 80 | } |
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