diff --git a/scratch/deepmind/part_two/reverse-words.py b/scratch/deepmind/part_two/reverse-words.py new file mode 100644 index 000000000..d433ac594 --- /dev/null +++ b/scratch/deepmind/part_two/reverse-words.py @@ -0,0 +1,63 @@ +import unittest + + +def reverse(xs, i, j): + """Reverse array of characters, xs, in-place.""" + while i < j: + xs[i], xs[j] = xs[j], xs[i] + i += 1 + j -= 1 + + +def reverse_words(xs): + reverse(xs, 0, len(xs) - 1) + i = 0 + j = i + while j < len(xs): + while j < len(xs) and xs[j] != ' ': + j += 1 + reverse(xs, i, j - 1) + j += 1 + i = j + + +# Tests +class Test(unittest.TestCase): + def test_one_word(self): + message = list('vault') + reverse_words(message) + expected = list('vault') + self.assertEqual(message, expected) + + def test_two_words(self): + message = list('thief cake') + reverse_words(message) + expected = list('cake thief') + self.assertEqual(message, expected) + + def test_three_words(self): + message = list('one another get') + reverse_words(message) + expected = list('get another one') + self.assertEqual(message, expected) + + def test_multiple_words_same_length(self): + message = list('rat the ate cat the') + reverse_words(message) + expected = list('the cat ate the rat') + self.assertEqual(message, expected) + + def test_multiple_words_different_lengths(self): + message = list('yummy is cake bundt chocolate') + reverse_words(message) + expected = list('chocolate bundt cake is yummy') + self.assertEqual(message, expected) + + def test_empty_string(self): + message = list('') + reverse_words(message) + expected = list('') + self.assertEqual(message, expected) + + +unittest.main(verbosity=2) diff --git a/scratch/deepmind/part_two/todo.org b/scratch/deepmind/part_two/todo.org index a3a3df6ef..91fd3fbf2 100644 --- a/scratch/deepmind/part_two/todo.org +++ b/scratch/deepmind/part_two/todo.org @@ -1,7 +1,7 @@ * Array and string manipulation ** DONE Merging Meeting Times ** DONE Reverse String in Place -** TODO Reverse Words +** DONE Reverse Words ** TODO Merge Sorted Arrays ** TODO Cafe Order Checker * Hashing and hash tables