This notebook was prepared by Donne Martin. Source and license info is on GitHub.

- Do the coins have to reach exactly n cents?
- Yes

- Can we assume we have an infinite number of coins to make n cents?
- Yes

- Do we need to report the combination(s) of coins that represent the minimum?
- No

- Can we assume the coin denominations are given in sorted order?
- No

- Can we assume this fits memory?
- Yes

- coins: None or n: None -> Exception
- coins: [] or n: 0 -> 0
- coins: [1, 2, 3], n: 5 -> 5

Refer to the Solution Notebook. If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start.

In [ ]:

```
class CoinChanger(object):
def make_change(self, coins, total):
# TODO: Implement me
return n
```

**The following unit test is expected to fail until you solve the challenge.**

In [ ]:

```
# %load test_coin_change.py
import unittest
class Challenge(unittest.TestCase):
def test_coin_change(self):
coin_changer = CoinChanger()
self.assertEqual(coin_changer.make_change([1, 2], 0), 0)
self.assertEqual(coin_changer.make_change([1, 2, 3], 5), 5)
self.assertEqual(coin_changer.make_change([1, 5, 25, 50], 10), 3)
print('Success: test_coin_change')
def main():
test = Challenge()
test.test_coin_change()
if __name__ == '__main__':
main()
```

Review the Solution Notebook for a discussion on algorithms and code solutions.