diff --git a/Sprint-2/improve_with_caches/fibonacci/fibonacci.py b/Sprint-2/improve_with_caches/fibonacci/fibonacci.py index 60cc667..7e92d1a 100644 --- a/Sprint-2/improve_with_caches/fibonacci/fibonacci.py +++ b/Sprint-2/improve_with_caches/fibonacci/fibonacci.py @@ -1,4 +1,12 @@ +cache = {} + def fibonacci(n): + if n in cache: + return cache[n] if n <= 1: - return n - return fibonacci(n - 1) + fibonacci(n - 2) + result = n + else: + result = fibonacci(n - 1) + fibonacci(n - 2) + + cache[n] = result + return result diff --git a/Sprint-2/improve_with_caches/making_change/making_change.py b/Sprint-2/improve_with_caches/making_change/making_change.py index 255612e..e675b49 100644 --- a/Sprint-2/improve_with_caches/making_change/making_change.py +++ b/Sprint-2/improve_with_caches/making_change/making_change.py @@ -1,5 +1,7 @@ from typing import List +cache = {} +coins = [1, 2, 5, 10, 20, 50, 100, 200] def ways_to_make_change(total: int) -> int: """ @@ -7,26 +9,30 @@ def ways_to_make_change(total: int) -> int: For instance, there are two ways to make a value of 3: with 3x 1 coins, or with 1x 1 coin and 1x 2 coin. """ - return ways_to_make_change_helper(total, [200, 100, 50, 20, 10, 5, 2, 1]) + return ways_to_make_change_helper(total, 0) + -def ways_to_make_change_helper(total: int, coins: List[int]) -> int: +def ways_to_make_change_helper(total: int, index: int) -> int: + key = (total, index) + if key in cache: + return cache[key] """ Helper function for ways_to_make_change to avoid exposing the coins parameter to callers. """ - if total == 0 or len(coins) == 0: + if total == 0: + cache[key] = 1 + return 1 + + if index == len(coins): + cache[key] = 0 return 0 + coin=coins[index] ways = 0 - for coin_index in range(len(coins)): - coin = coins[coin_index] - count_of_coin = 1 - while coin * count_of_coin <= total: - total_from_coins = coin * count_of_coin - if total_from_coins == total: - ways += 1 - else: - intermediate = ways_to_make_change_helper(total - total_from_coins, coins=coins[coin_index+1:]) - ways += intermediate - count_of_coin += 1 - return ways + count = 0 + while coin * count <= total: + ways += ways_to_make_change_helper(total - coin * count, index + 1) + count +=1 + cache[key] = ways + return ways \ No newline at end of file