tvl-depot/scratch/data_structures_and_algorithms/coins.py
William Carroll fabf1c9334 Tidy up structure of briefcase
I had a spare fifteen minutes and decided that I should tidy up my
monorepo. The work of tidying up is not finished; this is a small step in the
right direction.

TL;DR
- Created a tools directory
- Created a scratch directory (see README.md for more information)
- Added README.md to third_party
- Renamed delete_dotfile_symlinks -> symlinkManager
- Packaged symlinkManager as an executable symlink-mgr using buildGo
2020-02-12 16:58:29 +00:00

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)