Time - Quin

lib/exercises.rb

@@ -1,19 +1,45 @@
 
 # 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(m + n + nlog(n))
+# Space Complexity: O(n)
 
 def grouped_anagrams(strings)
-  raise NotImplementedError, "Method hasn't been implemented yet!"
+  grouped = {}
+  strings.each do |e|
+    current_sorted = e.split("").sort.join("") 
+    if !grouped["#{current_sorted}"]
+       grouped["#{current_sorted}"] = [e]
+    else
+      grouped["#{current_sorted}"] << e
+    end 
+  end 
+  return grouped.values
 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 log(n))
+# Space Complexity: O(n)
 def top_k_frequent_elements(list, k)
-  raise NotImplementedError, "Method hasn't been implemented yet!"
+  if list.length == 0 
+    return []
+  end 
+  nums = {}
+  list.each do |num|
+    if !nums[num]
+      nums[num] = 1
+    else
+      nums[num] += 1
+    end
+  end 
+
+  sorted = nums.sort_by {|k, v| -v}
+  top_k = []
+  k.times do |k|
+    top_k << sorted[k][0]
+  end 
+  return top_k
 end
 
 
@@ -27,3 +53,7 @@ def top_k_frequent_elements(list, k)
 def valid_sudoku(table)
   raise NotImplementedError, "Method hasn't been implemented yet!"
 end
+
+
+
+    #if col + 1 % 3 == 0  && row + 1 % 3 == 0 -> check square