回答編集履歴
1
再帰コード追加
test
CHANGED
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@@ -35,3 +35,69 @@
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35
35
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> すべての変数の値が常に変更されるのは保守の都合上よろしくない。
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確かにその通りですが、このコードはそんなに複雑じゃないと思います。
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38
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40
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41
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変数に再代入が無いように書くとこうなります。
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42
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43
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```Ruby
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44
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45
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class B
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46
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47
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def binary_search(arr, target)
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48
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left = 0
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50
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51
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right = arr.size - 1
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52
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return binary_search_rec(arr, target, left, right)
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54
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end
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58
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def binary_search_rec(arr, target, left, right)
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60
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if(left > right)
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return false
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end
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66
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mid = (left + right) / 2
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68
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69
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if(arr[mid] == target)
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70
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return true
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end
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74
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75
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if(arr[mid] < target)
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return binary_search_rec(arr, target, mid+ 1, right)
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end
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80
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81
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return binary_search_rec(arr, target, left, mid- 1)
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82
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end
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84
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end
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86
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87
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89
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#------------------------------
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90
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91
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92
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93
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find_at = B.new
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94
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arr = (1..10).to_a
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96
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97
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puts find_at.binary_search(arr, 9) #true
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puts find_at.binary_search(arr, 1) #true
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puts find_at.binary_search(arr, 109) #false
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102
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```
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