Amy M. #8
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,30 +1,144 @@ | ||
| # This method will return an array of arrays. | ||
| # Each subarray will have strings which are anagrams of each other | ||
| # Time Complexity: O(n) | ||
| # Space Complexity: O(n) | ||
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| def grouped_anagrams(strings) | ||
| if strings.length == 0 | ||
| return [] | ||
| end | ||
| word_hash = {} | ||
| strings.each do |word| | ||
| sorted_word = word.split("").sort().join() | ||
| if word_hash[sorted_word].nil? | ||
| word_hash[sorted_word] = [] | ||
| end | ||
| word_hash[sorted_word] << word | ||
| end | ||
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| anagrams = [] | ||
| word_hash.keys.each do |key| | ||
| anagrams << word_hash[key] | ||
| end | ||
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| return anagrams | ||
| end | ||
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| # This method will return the k most common elements | ||
| # in the case of a tie it will select the first occuring element. | ||
| # Time Complexity: O(n) | ||
| # Space Complexity: O(n) | ||
| def top_k_frequent_elements(list, k) | ||
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| if list.length == 0 | ||
| return [] | ||
| end | ||
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| count_hash = {} | ||
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| list.each do |char| | ||
| count_hash[char] ? count_hash[char] += 1 : count_hash[char] = 1 | ||
| end | ||
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| char_count = {} | ||
| count_hash.keys.each do |key| | ||
| char_count[count_hash[key]] ||= [] | ||
| char_count[count_hash[key]] << key | ||
| end | ||
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| num_remain = k | ||
| max = char_count.keys.max | ||
| most_frequent = [] | ||
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| while num_remain > 0 && max > 0 | ||
| if char_count[max] | ||
| char_count[max].each do |num| | ||
| most_frequent << num | ||
| num_remain -= 1 | ||
| break if num_remain == 0 | ||
| end | ||
| end | ||
| max -= 1 | ||
| end | ||
| return most_frequent | ||
| end | ||
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| # This method will return the true if the table is still | ||
| # a valid sudoku table. | ||
| # Each element can either be a ".", or a digit 1-9 | ||
| # The same digit cannot appear twice or more in the same | ||
| # row, column or 3x3 subgrid | ||
| # Time Complexity: ? | ||
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| # Space Complexity: ? | ||
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| # returns a hash of a valid sudoku row | ||
| def get_valid_sudoku | ||
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| sudoku = { | ||
| "1" => 1, | ||
| "2" => 1, | ||
| "3" => 1, | ||
| "4" => 1, | ||
| "5" => 1, | ||
| "6" => 1, | ||
| "7" => 1, | ||
| "8" => 1, | ||
| "9" => 1, | ||
| } | ||
| return sudoku | ||
| end | ||
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| # checks if row is valid | ||
| def valid_row?(row) | ||
| valid_row = get_valid_sudoku | ||
| row.each do |char| | ||
| if valid_row[char] | ||
| valid_row[char] -= 1 | ||
| if valid_row[char] < 0 | ||
| return false | ||
| end | ||
| end | ||
| end | ||
| return true | ||
| end | ||
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| # creates subsections | ||
| def create_sub_sections(table) | ||
| # code snippet from https://stackoverflow.com/questions/41020695/how-do-i-split-a-9x9-array-into-9-3x3-components | ||
| table.each_slice(3).map { |row| row.transpose.each_slice(3).map { |section| section.transpose } }.flatten(1) | ||
|
There was a problem hiding this comment. Very slick! I'm glad you cited where you got this. |
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| end | ||
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| # checks if subsection is valid | ||
| def valid_sub_section?(section) | ||
| valid_section = get_valid_sudoku | ||
| section.each do |row| | ||
| row.each do |num| | ||
| if valid_section[num] | ||
| valid_section[num] -= 1 | ||
| if valid_section[num] < 0 | ||
| return false | ||
| end | ||
| end | ||
| end | ||
| end | ||
| end | ||
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| def valid_sudoku(table) | ||
| # checks for valid rows | ||
| table.each do |row| | ||
| return false if !valid_row?(row) | ||
| end | ||
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| # checks for valid columns | ||
| trans_table = table.transpose() | ||
| trans_table.each do |col| | ||
| return false if !valid_row?(col) | ||
| end | ||
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| # checks for valid subsections | ||
| sub_sections = create_sub_sections(table) | ||
| sub_sections.each do |section| | ||
| if !valid_sub_section?(section) | ||
| return false | ||
| end | ||
| end | ||
| return true | ||
| end | ||
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Where the words are small, yes.