Kelly

lib/exercises.rb

@@ -2,11 +2,17 @@
 
 # This method will return an array of arrays.
 # Each subarray will have strings which are anagrams of each other
-# Time Complexity: ?
-# Space Complexity: ?
+# Time Complexity: O(n)
+# Space Complexity: O(n)
 
 def grouped_anagrams(strings)
-  raise NotImplementedError, "Method hasn't been implemented yet!"
+  grouped = Hash.new([])
+
+  strings.each.with_index do |word, i|
+    grouped[word.chars.sort.join] += [i]
+  end
+
+  return grouped.map { |key, indices| indices.map { |i| strings[i] } }
 end
 
 # This method will return the k most common elements
@@ -17,14 +23,13 @@ def top_k_frequent_elements(list, k)
   raise NotImplementedError, "Method hasn't been implemented yet!"
 end
 
-
 # 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 
+#   The same digit cannot appear twice or more in the same
 #   row, column or 3x3 subgrid
 # Time Complexity: ?
 # Space Complexity: ?
 def valid_sudoku(table)
   raise NotImplementedError, "Method hasn't been implemented yet!"
-end
+end