From feb00c47d3421f70d495f0f5870aa5e113344ccf Mon Sep 17 00:00:00 2001
From: Jing <60051579+Jing-321@users.noreply.github.com>
Date: Wed, 21 Apr 2021 23:04:30 -0700
Subject: [PATCH] complete

---
 lib/exercises.rb | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/lib/exercises.rb b/lib/exercises.rb
index e1b3850..ebb51c6 100644
--- a/lib/exercises.rb
+++ b/lib/exercises.rb
@@ -1,11 +1,26 @@
 
 # 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!"
+  words = Hash.new
+
+  strings.each do |string|
+    letter_count = Hash.new
+    string.each_char do |c|
+      letter_count[c] = letter_count[c] ? letter_count[c] + 1 : 1
+    end
+
+    if words[letter_count]
+      words[letter_count].push(string)
+    else
+      words[letter_count] = [string]
+    end
+  end
+
+  return words.values
 end
 
 # This method will return the k most common elements
@@ -13,7 +28,13 @@ def grouped_anagrams(strings)
 # Time Complexity: ?
 # Space Complexity: ?
 def top_k_frequent_elements(list, k)
-  raise NotImplementedError, "Method hasn't been implemented yet!"
+  element_count = {}
+  
+  list.each do |element|
+    element_count[element] = element_count[element] ? element_count[element] + 1 : 1
+  end
+
+  return element_count.max_by(k) {|a| a[1]}.map {|a| a[0]}
 end