Branches - Emily Ball

lib/reverse_sentence.rb

@@ -1,6 +1,28 @@
 # A method to reverse the words in a sentence, in place.
-# Time complexity: ?
-# Space complexity: ?
+# Time complexity: O(n^2)
+# Space complexity: O(n)
+
+# Doesn't reverse in place - still working 
+
 def reverse_sentence(my_sentence)
-  raise NotImplementedError
+  if my_sentence == nil
+    return nil
+  elsif my_sentence == ""
+    return ""
+  end
+  words = my_sentence.split(/(\s)/)
+  return my_sentence if words.length < 2
+
+  hi = words.length - 1
+  low = 0
+  until low >= hi
+    bottom = words[low]
+    top = words[hi]
+    words[low] = top
+    words[hi] = bottom
+    hi -= 1
+    low += 1
+  end
+  my_sentence = words.join
+  return my_sentence
 end

lib/sort_by_length.rb

@@ -1,7 +1,23 @@
 # A method which will return an array of the words in the string
 #  sorted by the length of the word.
-# Time complexity: ?
-# Space complexity: ?
+# Time complexity: O(n^2)
+# Space complexity: O(1)
+
 def sort_by_length(my_sentence)
-  raise NotImplementedError, "Method not implemented"
-end
+  return [] if my_sentence == ""
+  array = my_sentence.split(" ")
+  length = array.length
+
+  i = 1
+  while i < length
+    to_insert = array[i]
+    j = i
+    while j > 0 && (array[j-1].length) > (to_insert.length)
+      array[j] = array[j-1]
+      j -= 1
+    end
+    array[j] = to_insert
+    i += 1
+  end
+  return array
+end

test/sort_by_length_test.rb

@@ -0,0 +1,19 @@
+# require_relative "test_helper"
+
+# describe "sort_by_length" do
+#   it "will return an empty array for an empty string" do
+#     expect(sort_by_length("")).must_equal []
+#   end
+
+#   it "will return an array of words, by length" do
+#     expect(sort_by_length("I love Ada")).must_equal ["I", "Ada", "love"]
+#   end
+
+#   it "will return an array of words by length, words that are of equal length will appear in the order they appear" do
+#     expect(sort_by_length("words of equal length")).must_equal ["of", "words", "equal", "length"]
+#   end
+
+#   it "will return an array of words by length, words that are of equal length will appear in the order they appear" do
+#     expect(sort_by_length("I love great awesome words")).must_equal ["I", "love", "great", "words", "awesome"]
+#   end
+# end