vi

lib/exercises.rb

@@ -2,20 +2,59 @@
 
 # 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!"
-end
+  anagram_hash = Hash.new
+
+  strings.each do |word|
+    sorted_string = word.chars.sort.join
+
+    #Check if key exists with the sorted string already
+    #In case of yes, add the word to the array value of the key  
+    if anagram_hash[sorted_string]
+      anagram_hash[sorted_string] += [word] 
+
+    #If not, set it as a new key/value pair in the hash
+    else 
+      anagram_hash[sorted_string] = [word]
+    end 
+  end 
+  return anagram_hash.valuesend
 
 # 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!"
-end
+  result = []
+
+  hash = Hash.new
+
+  list.each do |letter|
+    if hash[letter]
+      hash[letter] += 1
+    else 
+      hash[letter] = 1
+    end 
+  end 
+
+  k.times do 
+    max = nil
+    hash.each do |num, value|
+
+      if value && (max.nil? || value > max)
+        max = num 
+      end 
+    end 
+
+    if max 
+      hash[max] = nil 
+      result << max 
+    end 
+  end 
+  return result end
 
 
 # This method will return the true if the table is still

test/exercises_test.rb

@@ -68,7 +68,7 @@
     end
   end
 
-  xdescribe "top_k_frequent_elements" do
+  describe "top_k_frequent_elements" do
     it "works with example 1" do
       # Arrange
       list = [1,1,1,2,2,3]