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.
This commit is contained in:
William Carroll 2020-01-18 17:04:05 +00:00
parent a62553f7b7
commit 34dc3e05c8
3 changed files with 161 additions and 0 deletions

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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)

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import unittest
def merge_ranges(xs):
xs.sort()
result = [xs[0]]
for curr in xs[1:]:
a, z = result[-1]
if z >= curr[0]:
result[-1] = (a, max(z, curr[1]))
else:
result.append(curr)
return result
# Tests
class Test(unittest.TestCase):
def test_meetings_overlap(self):
actual = merge_ranges([(1, 3), (2, 4)])
expected = [(1, 4)]
self.assertEqual(actual, expected)
def test_meetings_touch(self):
actual = merge_ranges([(5, 6), (6, 8)])
expected = [(5, 8)]
self.assertEqual(actual, expected)
def test_meeting_contains_other_meeting(self):
actual = merge_ranges([(1, 8), (2, 5)])
expected = [(1, 8)]
self.assertEqual(actual, expected)
def test_meetings_stay_separate(self):
actual = merge_ranges([(1, 3), (4, 8)])
expected = [(1, 3), (4, 8)]
self.assertEqual(actual, expected)
def test_multiple_merged_meetings(self):
actual = merge_ranges([(1, 4), (2, 5), (5, 8)])
expected = [(1, 8)]
self.assertEqual(actual, expected)
def test_meetings_not_sorted(self):
actual = merge_ranges([(5, 8), (1, 4), (6, 8)])
expected = [(1, 4), (5, 8)]
self.assertEqual(actual, expected)
def test_one_long_meeting_contains_smaller_meetings(self):
actual = merge_ranges([(1, 10), (2, 5), (6, 8), (9, 10), (10, 12)])
expected = [(1, 12)]
self.assertEqual(actual, expected)
def test_sample_input(self):
actual = merge_ranges([(0, 1), (3, 5), (4, 8), (10, 12), (9, 10)])
expected = [(0, 1), (3, 8), (9, 12)]
self.assertEqual(actual, expected)
unittest.main(verbosity=2)

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deepmind/stock-price.py Normal file
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def get_max_profit(xs):
best_profit = xs[1] - xs[0]
lowest_buy = xs[0]
for x in xs[1:]:
best_profit = max(best_profit, x - lowest_buy)
lowest_buy = min(lowest_buy, x)
return best_profit
# Tests
import unittest
class Test(unittest.TestCase):
def test_price_goes_up_then_down(self):
actual = get_max_profit([1, 5, 3, 2])
expected = 4
self.assertEqual(actual, expected)
def test_price_goes_down_then_up(self):
actual = get_max_profit([7, 2, 8, 9])
expected = 7
self.assertEqual(actual, expected)
def test_price_goes_up_all_day(self):
actual = get_max_profit([1, 6, 7, 9])
expected = 8
self.assertEqual(actual, expected)
def test_price_goes_down_all_day(self):
actual = get_max_profit([9, 7, 4, 1])
expected = -2
self.assertEqual(actual, expected)
def test_price_stays_the_same_all_day(self):
actual = get_max_profit([1, 1, 1, 1])
expected = 0
self.assertEqual(actual, expected)
def test_error_with_empty_prices(self):
with self.assertRaises(Exception):
get_max_profit([])
def test_error_with_one_price(self):
with self.assertRaises(Exception):
get_max_profit([1])
unittest.main(verbosity=2)