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* Retranslate the complete Japanese online edition from Chinese * Fit Japanese homepage labels and localize heading permalinks * Point Japanese contribution instructions to the Japanese preview * Replace locale conditionals with multilingual UI tables
47 lines
1.0 KiB
Ruby
47 lines
1.0 KiB
Ruby
=begin
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File: two_sum.rb
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Created Time: 2024-04-09
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Author: Blue Bean (lonnnnnnner@gmail.com)
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=end
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### 方法 1：総当たり列挙 ###
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def two_sum_brute_force(nums, target)
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# 二重ループのため、時間計算量は O(n^2)
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for i in 0...(nums.length - 1)
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for j in (i + 1)...nums.length
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return [i, j] if nums[i] + nums[j] == target
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end
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end
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[]
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end
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### 方法 2：補助ハッシュテーブル ###
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def two_sum_hash_table(nums, target)
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# 補助ハッシュテーブルの空間計算量は O(n)
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dic = {}
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# 一重ループのため、時間計算量は O(n)
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for i in 0...nums.length
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return [dic[target - nums[i]], i] if dic.has_key?(target - nums[i])
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dic[nums[i]] = i
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end
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[]
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end
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### 実行用コード ###
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if __FILE__ == $0
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# ======= テストケース =======
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nums = [2, 7, 11, 15]
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target = 13
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# ====== 実行用コード ======
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# 方法 1
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res = two_sum_brute_force(nums, target)
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puts "方法 1 res = #{res}"
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# 方法 2
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res = two_sum_hash_table(nums, target)
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puts "方法 2 res = #{res}"
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end
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