From bac6f91b92e02c53dc32b7f8ecafe779361bd5d9 Mon Sep 17 00:00:00 2001
From: denisseai <msdenisseanaya@gmail.com>
Date: Thu, 17 Sep 2020 20:33:10 -0700
Subject: [PATCH 1/3] HW done

---
 lib/exercises.rb | 46 ++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 42 insertions(+), 4 deletions(-)

diff --git a/lib/exercises.rb b/lib/exercises.rb
index e1b3850..f3a47fb 100644
--- a/lib/exercises.rb
+++ b/lib/exercises.rb
@@ -1,19 +1,57 @@
 
 # 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: a lot
+# Space Complexity: O(n)
 
 def grouped_anagrams(strings)
-  raise NotImplementedError, "Method hasn't been implemented yet!"
+  hash = {}
+
+  strings.each do | string | 
+
+   a_key = string.chars.sort
+
+   if hash.key? (a_key)
+     hash[a_key] << string 
+   else
+     hash[a_key] = [string]
+   end
+  end 
+
+   arrayArrays = []
+   hash.each do | key , value|
+     arrayArrays << hash[key]
+   end
+
+   return arrayArrays 
 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: ?
+# resource: https://stackoverflow.com/questions/4264133/descending-sort-by-value-of-a-hash-in-ruby
 def top_k_frequent_elements(list, k)
-  raise NotImplementedError, "Method hasn't been implemented yet!"
+  # Hash.new(0) sets default value for any key to 0, while {} sets nil
+  hash = Hash.new(0)
+  k_array = []
+
+  return [] if list.empty?
+  
+  # populate the hash and count occurrence
+  list.each do |num|
+    hash[num] += 1
+  end
+
+  # set hash's values in descending order
+  descending_hash = hash.sort_by {|key, value| -value}
+
+  # populate the array with most common elements dictated by k
+  k.times do |i|
+    k_array << descending_hash[i][0]
+  end
+
+  return k_array
 end
 
 

From d6b108370b7b18986e26b8f8cd0fd08a31feeef1 Mon Sep 17 00:00:00 2001
From: denisseai <26889152+denisseai@users.noreply.github.com>
Date: Thu, 24 Sep 2020 20:06:41 -0700
Subject: [PATCH 2/3] Update lib/exercises.rb

Co-authored-by: Chris M <chris@adadevelopersacademy.org>
---
 lib/exercises.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/exercises.rb b/lib/exercises.rb
index f3a47fb..5289d81 100644
--- a/lib/exercises.rb
+++ b/lib/exercises.rb
@@ -11,7 +11,7 @@ def grouped_anagrams(strings)
 
    a_key = string.chars.sort
 
-   if hash.key? (a_key)
+   if hash[a_key]
      hash[a_key] << string 
    else
      hash[a_key] = [string]

From df2184e258ac53f8f075795b43b0556df0182701 Mon Sep 17 00:00:00 2001
From: denisseai <26889152+denisseai@users.noreply.github.com>
Date: Thu, 24 Sep 2020 20:07:17 -0700
Subject: [PATCH 3/3] Update lib/exercises.rb

Co-authored-by: Chris M <chris@adadevelopersacademy.org>
---
 lib/exercises.rb | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/lib/exercises.rb b/lib/exercises.rb
index 5289d81..bc2b9e8 100644
--- a/lib/exercises.rb
+++ b/lib/exercises.rb
@@ -18,12 +18,7 @@ def grouped_anagrams(strings)
    end
   end 
 
-   arrayArrays = []
-   hash.each do | key , value|
-     arrayArrays << hash[key]
-   end
-
-   return arrayArrays 
+   return hash.values
 end
 
 # This method will return the k most common elements