challenge-28.md

Challenge #28 - Growing & Shrinking Potions

There are two types of potions:

Growing potion: "A" Shrinking potion: "B"

• If "A" immediately follows a digit, add 1 to the proceeding number.
• If "B" immediately follows a digit, subtract 1 from the proceeding number.

Create a function that returns a string according to these rules, removing the potions once they've been consumed.

Examples

apply_potions("3A78B51") ➞ "47751"
# 3 grows to 4, 78 shrinks to 77

apply_potions("9999B") ➞ "9998"

apply_potions("9A123") ➞ "10123"

apply_potions("567") ➞ "567"

Notes

• Numbers that are not followed by a potion on their immediate right should be left alone.
• A number will always either be followed by zero or exactly 1 potion.

challenge_tests.py

import unittest


def apply_potions(potions: str) -> str:
    return ""  # Replace with your own code!!!


class TestPotions(unittest.TestCase):
    def test_1(self):
        self.assertEqual(apply_potions("567"), "567")

    def test_2(self):
        self.assertEqual(apply_potions("3A78B51"), "47751")

    def test_3(self):
        self.assertEqual(apply_potions("9999B"), "9998")

    def test_4(self):
        self.assertEqual(apply_potions("9A123"), "10123")

    def test_5(self):
        self.assertEqual(apply_potions("1A2A3A4A"), "2345")

    def test_6(self):
        self.assertEqual(apply_potions("9B8B7B6A"), "8767")

    def test_7(self):
        self.assertEqual(apply_potions("19A10B99A1000B"), "209100999")


if __name__ == "__main__":
    unittest.main()

credits.md

Adapted from a challenge found on Edabit: Growing and Shrinking Potions