Niv

lib/exercises.rb

@@ -2,13 +2,32 @@
 
 # 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 * mlogm)
+# n for .each do, mlogm for sort
+# Space Complexity: O(n)
+
 
 def grouped_anagrams(strings)
-  raise NotImplementedError, "Method hasn't been implemented yet!"
+  output = []
+  anagram = {}
+
+  strings.each do |word|
+    key = word.split("").sort
+    if anagram.has_key?(key) == true
+      anagram[key].push(word)
+    else
+      anagram[key] = [word]
+    end
+  end
+
+  anagram.each_key do |key|
+    output.push(anagram[key])
+  end
+
+  return output
 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: ?
@@ -26,5 +45,57 @@ def top_k_frequent_elements(list, k)
 # Time Complexity: ?
 # Space Complexity: ?
 def valid_sudoku(table)
-  raise NotImplementedError, "Method hasn't been implemented yet!"
+  if check_rows(table) == false || check_columns(table) == false || check_subgrid(table) == false
+    return false
+  end
+  return true
+end
+
+def check_unique(array)
+  new_array = array.keep_if{|element| element != "."}
+  new_array = new_array.uniq
+  if new_array.length < array.length
+    return false
+  end
+  return true
+end
+
+def check_rows(table)
+  table.each do |row|
+    if check_unique(row) == false
+      return false
+    end
+  end
+  return true
+end
+
+def check_columns(table)
+  i = 0
+  j = 0
+  column = []
+  for i < table.length
+    for j < table.length
+      column.push(table[j][i])
+      j += 1
+      if j == table.length - 1
+        if check_unique(column) == false
+          return false
+        end
+      end
+    end
+    i += 1
+    j = 0
+    column = []
+  end
+  return true
+end
+
+def check_subgrid(table)
+  subgrids = {}
+  i = 0
+  for i < table.length
+    subgrids[i] = []
+
+
+  end
 end