Complete practice algorithms from InterviewCake.com

While I've done these algorithms before, I'm preparing for an on-site with
DeepMind, so I created a subdirectory called deepmind where I'm storing my
second attempts at these problems. The idea of storing them in a second
directory is to remove the urge to check my existing solutions that also exist
in this repository.

deepmind/inflight-entertainment.py

@@ -0,0 +1,51 @@
+import unittest
+
+
+def can_two_movies_fill_flight(xs, t):
+    seeking = set()
+    for x in xs:
+        if x in seeking:
+            return True
+        else:
+            seeking.add(t - x)
+    return False
+
+
+# Tests
+
+
+class Test(unittest.TestCase):
+    def test_short_flight(self):
+        result = can_two_movies_fill_flight([2, 4], 1)
+        self.assertFalse(result)
+
+    def test_long_flight(self):
+        result = can_two_movies_fill_flight([2, 4], 6)
+        self.assertTrue(result)
+
+    def test_one_movie_half_flight_length(self):
+        result = can_two_movies_fill_flight([3, 8], 6)
+        self.assertFalse(result)
+
+    def test_two_movies_half_flight_length(self):
+        result = can_two_movies_fill_flight([3, 8, 3], 6)
+        self.assertTrue(result)
+
+    def test_lots_of_possible_pairs(self):
+        result = can_two_movies_fill_flight([1, 2, 3, 4, 5, 6], 7)
+        self.assertTrue(result)
+
+    def test_not_using_first_movie(self):
+        result = can_two_movies_fill_flight([4, 3, 2], 5)
+        self.assertTrue(result)
+
+    def test_only_one_movie(self):
+        result = can_two_movies_fill_flight([6], 6)
+        self.assertFalse(result)
+
+    def test_no_movies(self):
+        result = can_two_movies_fill_flight([], 2)
+        self.assertFalse(result)
+
+
+unittest.main(verbosity=2)