回答編集履歴
3
対案を提示
answer
CHANGED
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@@ -31,4 +31,39 @@
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31
31
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[Tablet, SmartPhone, Notebook, MobilePhone]
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32
32
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```
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33
33
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34
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-
http://docs.oracle.com/javase/jp/7/api/java/util/Collections.html#reverse(java.util.List)
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34
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+
http://docs.oracle.com/javase/jp/7/api/java/util/Collections.html#reverse(java.util.List)
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35
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+
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36
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+
## 対案 : ソートを1回だけ実行する
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37
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+
swordone様のご指摘を受け、ソート処理を1回で済ませるプログラムを以下に示します。
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38
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+
`Collections.reverseOrder()`メソッドを使用しております。
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39
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+
```java
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40
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+
import java.util.ArrayList;
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41
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+
import java.util.Collections;
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42
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import java.util.Comparator;
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43
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import java.util.List;
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44
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45
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public class Main {
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46
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47
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public static void main(String[] args) {
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48
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List<String> devicesList = new ArrayList<String>();
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49
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devicesList.add("SmartPhone");
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50
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devicesList.add("Tablet");
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51
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devicesList.add("MobilePhone");
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52
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devicesList.add("Notebook");
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53
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+
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54
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System.out.println(devicesList);
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55
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+
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56
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Comparator<String> reverseOrder = Collections.reverseOrder();
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57
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Collections.sort(devicesList, reverseOrder);
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58
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System.out.println(devicesList);
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59
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}
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60
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+
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61
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}
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62
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```
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63
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実行結果
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64
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```
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65
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[SmartPhone, Tablet, MobilePhone, Notebook]
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66
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+
[Tablet, SmartPhone, Notebook, MobilePhone]
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67
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```
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68
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+
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69
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+
http://docs.oracle.com/javase/jp/7/api/java/util/Collections.html#reverseOrder(java.util.Comparator)
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2
文言を修正
answer
CHANGED
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@@ -1,4 +1,4 @@
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1
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-
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1
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+
`Collections.reverse()`メソッドを使用すれば、`Comparator`クラスを実装しなくても実現できます。
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2
2
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```java
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3
3
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import java.util.ArrayList;
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4
4
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import java.util.Collections;
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1
リンクを追記
answer
CHANGED
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@@ -29,4 +29,6 @@
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29
29
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[SmartPhone, Tablet, MobilePhone, Notebook]
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30
30
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[MobilePhone, Notebook, SmartPhone, Tablet]
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31
31
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[Tablet, SmartPhone, Notebook, MobilePhone]
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32
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-
```
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32
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+
```
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33
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+
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34
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+
http://docs.oracle.com/javase/jp/7/api/java/util/Collections.html#reverse(java.util.List)
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