Amy P

lib/exercises.rb

@@ -1,20 +1,43 @@
-
-
 # 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) where n is the number of elements in the array
+# Space Complexity: O(n)
 
 def grouped_anagrams(strings)
-  raise NotImplementedError, "Method hasn't been implemented yet!"
+  return [] if strings.length == 0
+
+  hash = {}
+  strings.each do |word|
+    sorted_word = word.split("").sort
+    if hash[sorted_word]
+      hash[sorted_word] << word
+    end
+  end
+  final_anagrams = []
+    hash.each do |k, v|
+      anagrams << v
+    end
+    return final_anagrams
 end
 
 # This method will return the k most common elements
 # in the case of a tie it will select the first occuring element.
-# Time Complexity: ?
-# Space Complexity: ?
+# Time Complexity: O(n)
+# Space Complexity: O(n)
+
 def top_k_frequent_elements(list, k)
-  raise NotImplementedError, "Method hasn't been implemented yet!"
+  hash = {}
+
+  list.each do |value|
+    if hash[value]
+      hash[value] += 1
+    else
+      hash[value] = 1
+    end
+  end
+
+  top_elements = Array.new(k)
+  return top_elements = hash.sort_by{ |key, value| value } 
 end