回答編集履歴
3
一番簡単なコードかな？
test
CHANGED
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@@ -81,3 +81,31 @@
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81
81
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`for (int i = 16; i > 0; s += (char)('0'+(n >> --i & 1))) ;` の方が
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82
82
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83
83
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メソッド `charAt` の呼び出しが無くて速いかも。でも += は遅いでしょう。
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84
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+
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85
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+
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86
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+
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87
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+
**追記3**
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88
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+
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89
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+
これが一番簡単かな？
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90
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+
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91
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+
```Java
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92
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+
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93
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+
class Test {
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94
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+
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95
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+
static String bin16(int n) {
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96
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+
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97
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return Integer.toBinaryString(0x10000 + n).substring(1);
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98
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+
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99
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}
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100
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+
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101
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+
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102
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103
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+
public static void main(String[] args) {
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104
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105
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System.out.println(bin16(127));
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106
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+
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107
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}
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108
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+
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109
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}
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110
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+
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111
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```
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2
forで回すコードを追加
test
CHANGED
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@@ -49,3 +49,35 @@
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49
49
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}
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50
50
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51
51
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```
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52
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+
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53
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**追記2**
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54
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+
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55
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+
さらに別解
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56
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+
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57
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+
```Java
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58
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+
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59
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+
class Test {
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60
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+
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61
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static String bin16(int n) {
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62
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63
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String s = "";
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64
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65
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for (int i = 16; i > 0; s += "01".charAt(n >> --i & 1)) ;
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66
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67
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return s;
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68
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+
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69
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}
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70
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+
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71
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public static void main(String[] args) {
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72
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73
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System.out.println(bin16(127));
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74
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+
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75
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}
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76
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+
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77
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}
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78
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+
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79
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```
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80
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+
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81
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+
`for (int i = 16; i > 0; s += (char)('0'+(n >> --i & 1))) ;` の方が
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82
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+
|
|
83
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+
メソッド `charAt` の呼び出しが無くて速いかも。でも += は遅いでしょう。
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1
別解の追加
test
CHANGED
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@@ -21,3 +21,31 @@
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21
21
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}
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22
22
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23
23
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```
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24
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+
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25
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**追記**
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26
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27
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+
別解
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28
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+
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29
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+
```Java
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30
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+
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31
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class Test {
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32
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+
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33
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static String bin16(int n) {
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34
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+
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35
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String s = "000000000000000" + Integer.toBinaryString(n);
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36
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+
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37
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return s.substring(s.length() - 16);
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38
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39
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}
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40
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+
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41
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+
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42
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43
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public static void main(String[] args) {
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44
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+
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45
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System.out.println(bin16(127));
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46
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+
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47
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+
}
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48
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+
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49
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}
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50
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+
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51
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+
```
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