mirror of
https://github.com/TheAlgorithms/Ruby
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51 lines
1.1 KiB
Ruby
51 lines
1.1 KiB
Ruby
# Challenge name: Find Common Characters
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#
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# Given an array A of strings made only from lowercase letters, return a list
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# of all characters that show up in all strings within the list
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# (including duplicates). For example, if a character occurs 3 times in all
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# strings but not 4 times, you need to include that character three times in
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# the final answer.
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#
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# You may return the answer in any order.
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#
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# Example 1:
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# Input: ["bella","label","roller"]
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# Output: ["e","l","l"]
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#
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# Example 2:
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# Input: ["cool","lock","cook"]
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# Output: ["c","o"]
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#
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# Approach 1: Hash
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#
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# Time Complexity: O(n)
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#
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def common_characters(arr)
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target_count = arr.count
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hash = Hash.new(0)
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(0...target_count).each do |i|
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arr[i].split('').each do |letter|
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hash[letter] += 1
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end
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end
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result = []
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hash.each do |k, v|
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while v >= target_count
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if v >= target_count
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result << k
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v -= target_count
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end
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end
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end
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result
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end
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puts common_characters(%w[bella label roller])
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# => ["e","l","l"]
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puts common_characters(%w[cool lock cook])
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# => ["c","o"]
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