d4d8397e5f
Adds some of the code I generated while studying for a role transfer at Google using the fantastic resource, InterviewCake.com. This work predates the mono-repo. I should think of ways to DRY up this code and the code in crack_the_coding_interview, but I'm afraid I'm creating unnecessary work for myself that way.
57 lines
1.6 KiB
Python
57 lines
1.6 KiB
Python
import unittest
|
|
from math import floor
|
|
|
|
################################################################################
|
|
# Solution
|
|
################################################################################
|
|
|
|
# change_possibilities :: Int -> [Int] -> Int
|
|
def change_possibilities(n, xs):
|
|
combinations = [0] * (n + 1)
|
|
combinations[0] = 1
|
|
|
|
for x in xs:
|
|
for i in range(len(combinations)):
|
|
if i >= x:
|
|
combinations[i] += combinations[i - x]
|
|
|
|
return combinations[n]
|
|
|
|
|
|
################################################################################
|
|
# Tests
|
|
################################################################################
|
|
class Test(unittest.TestCase):
|
|
|
|
def test_sample_input(self):
|
|
actual = change_possibilities(4, (1, 2, 3))
|
|
expected = 4
|
|
self.assertEqual(actual, expected)
|
|
|
|
def test_one_way_to_make_zero_cents(self):
|
|
actual = change_possibilities(0, (1, 2))
|
|
expected = 1
|
|
self.assertEqual(actual, expected)
|
|
|
|
def test_no_ways_if_no_coins(self):
|
|
actual = change_possibilities(1, ())
|
|
expected = 0
|
|
self.assertEqual(actual, expected)
|
|
|
|
def test_big_coin_value(self):
|
|
actual = change_possibilities(5, (25, 50))
|
|
expected = 0
|
|
self.assertEqual(actual, expected)
|
|
|
|
def test_big_target_amount(self):
|
|
actual = change_possibilities(50, (5, 10))
|
|
expected = 6
|
|
self.assertEqual(actual, expected)
|
|
|
|
def test_change_for_one_dollar(self):
|
|
actual = change_possibilities(100, (1, 5, 10, 25, 50))
|
|
expected = 292
|
|
self.assertEqual(actual, expected)
|
|
|
|
|
|
unittest.main(verbosity=2)
|