Created
November 10, 2023 03:09
-
-
Save shiracamus/d9e174a352c0048f2e39acfb74d8f1c6 to your computer and use it in GitHub Desktop.
四則演算を使わない加算処理（Qiitaに投稿された記事にコメントしたが記事は削除された）
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| import java.util.HashMap; | |
| import java.util.Map; | |
| class Digit { // 1桁数字 | |
| static final Map<Integer, Integer> next = new HashMap<>() {{ | |
| put(0, 1); | |
| put(1, 2); | |
| put(2, 3); | |
| put(3, 4); | |
| put(4, 5); | |
| put(5, 6); | |
| put(6, 7); | |
| put(7, 8); | |
| put(8, 9); | |
| put(9, 0); | |
| }}; | |
| protected int value = 0; | |
| public void increment() { | |
| value = next.get(value); | |
| } | |
| } | |
| public class Digits extends Digit { // 複数桁数字 | |
| private Digit carry = null; // 上位桁 | |
| public Digits(int value) { | |
| this.value = value; | |
| } | |
| @Override | |
| public void increment() { | |
| super.increment(); | |
| if (value == 0) { | |
| if (carry == null) { | |
| carry = new Digits(1); | |
| } else { | |
| carry.increment(); | |
| } | |
| } | |
| } | |
| public void plus(int value) { | |
| for (int i = 0; i < value; i++) { | |
| increment(); | |
| } | |
| } | |
| @Override | |
| public String toString() { | |
| return String.format("%s%d", carry == null ? "" : carry, value); | |
| } | |
| public static void main(String[] args) { | |
| Digits value = new Digits(6); | |
| System.out.println(value); | |
| value.plus(5); | |
| System.out.println(value); | |
| value.plus(12345678); | |
| System.out.println(value); | |
| } | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment