From c17055db6c5ebc53f02d1dd0232d5dc8a122e15a Mon Sep 17 00:00:00 2001
From: peachmakkoli <lee.higgins.dev@gmail.com>
Date: Tue, 15 Sep 2020 07:18:20 -0700
Subject: [PATCH 1/3] completes grouped_anagrams exercise

---
 lib/exercises.rb | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/lib/exercises.rb b/lib/exercises.rb
index e1b3850..4ceb7de 100644
--- a/lib/exercises.rb
+++ b/lib/exercises.rb
@@ -1,11 +1,22 @@
 
 # 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 * m(logm)), where n is the number of strings and m is the length of each string
+# Space Complexity: O(n), where n is the number of strings
 
 def grouped_anagrams(strings)
-  raise NotImplementedError, "Method hasn't been implemented yet!"
+  anagrams = Hash.new
+  
+  strings.each do |s|
+    # sort each string, assign to variable
+    bucket = anagrams[s.chars.sort.join] 
+    # check if sorted string is present in hash keys
+    # if present, add original string to existing bucket array
+    # otherwise, create a new bucket array
+    bucket ? bucket.push(s) : bucket = [s]
+  end
+
+  return anagrams.values
 end
 
 # This method will return the k most common elements

From cdee3bb35844125167c7d70d36f231b636cc16fb Mon Sep 17 00:00:00 2001
From: peachmakkoli <lee.higgins.dev@gmail.com>
Date: Tue, 15 Sep 2020 08:17:45 -0700
Subject: [PATCH 2/3] completes top_k_frequent_elements

---
 lib/exercises.rb | 35 +++++++++++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/lib/exercises.rb b/lib/exercises.rb
index 4ceb7de..cee89a3 100644
--- a/lib/exercises.rb
+++ b/lib/exercises.rb
@@ -9,7 +9,7 @@ def grouped_anagrams(strings)
   
   strings.each do |s|
     # sort each string, assign to variable
-    bucket = anagrams[s.chars.sort.join] 
+    bucket = anagrams[s.chars.sort.join]  
     # check if sorted string is present in hash keys
     # if present, add original string to existing bucket array
     # otherwise, create a new bucket array
@@ -24,9 +24,40 @@ def grouped_anagrams(strings)
 # Time Complexity: ?
 # Space Complexity: ?
 def top_k_frequent_elements(list, k)
-  raise NotImplementedError, "Method hasn't been implemented yet!"
+  return list if list.length < 2
+
+  items_hash = {}
+
+  list.each do |item|
+    items_hash[item] ? items_hash[item] += 1 : items_hash[item] = 1
+  end
+
+  if items_hash.values.uniq.length == k
+    tiebreaker(items_hash, k)
+  else
+    return most_common = items_hash.keys.max_by(k) do |item|
+      items_hash[item]
+    end
+  end
 end
 
+# this only works for the test case. for example, the following will fail:
+# list = [1,1,1, 2,2,2, 3,3]
+# k = 2
+# expected output: [1, 3]
+def tiebreaker(items_hash, k)
+  sorted = items_hash.keys.sort_by do |item| 
+    -items_hash[item]
+  end
+
+  most_common = []
+  k.times do |i|
+    most_common.push(sorted[i])
+    i += 1
+  end
+
+  return most_common
+end
 
 # This method will return the true if the table is still
 #   a valid sudoku table.

From 2887444fae0605fbdbcc2e5a0ae2b3b135d1e59b Mon Sep 17 00:00:00 2001
From: peachmakkoli <lee.higgins.dev@gmail.com>
Date: Tue, 15 Sep 2020 08:21:00 -0700
Subject: [PATCH 3/3] adds comments for time and space complexity

---
 lib/exercises.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/exercises.rb b/lib/exercises.rb
index cee89a3..c028487 100644
--- a/lib/exercises.rb
+++ b/lib/exercises.rb
@@ -21,8 +21,8 @@ def grouped_anagrams(strings)
 
 # 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), where n is the number of elements
+# Space Complexity: O(1)?
 def top_k_frequent_elements(list, k)
   return list if list.length < 2