class Solution:
    def groupAnagrams(self, strs: List[str]) -> List[List[str]]:
        pairs = [(''.join(sorted(string)), string) for string in strs]

        ordered_to_original = defaultdict(list)

        for ordered, original in pairs:
            ordered_to_original[ordered].append(original)

        return list(ordered_to_original.values())

# More concise solution:
class Solution:
    def groupAnagrams(self, strs: list[str]) -> list[list[str]]:
        s_to_list = defaultdict(list)

        for s in strs:
            s_to_list[
                ''.join(sorted(s))
            ].append(s)

        print(s_to_list) # defaultdict(<class 'list'>, {'aet': ['eat', 'tea', 'ate'], 'ant': ['tan', 'nat'], 'abt': ['bat']})

        return list(s_to_list.values())

# @param {String[]} strs
# @return {String[][]}
def group_anagrams(strs)
  result = Hash.new([])
  strs.each do |str|
    result[str.chars.sort.join] += [str]
  end
  result.values
end

# Or solution 2: More concise way

# @param {String[]} strs
# @return {String[][]}
def group_anagrams(strs)
  strs.group_by { |string| string.chars.sort }.values
end