From d5efde93d038895a76b3ace4d44724c2fd7335b3 Mon Sep 17 00:00:00 2001 From: TarasMykytiuk Date: Sun, 28 Jun 2026 01:03:50 +0100 Subject: [PATCH 1/2] improve_with_cache --- .../fibonacci/fibonacci.py | 8 +++- .../making_change/making_change.py | 38 +++++++++++-------- 2 files changed, 30 insertions(+), 16 deletions(-) diff --git a/Sprint-2/improve_with_caches/fibonacci/fibonacci.py b/Sprint-2/improve_with_caches/fibonacci/fibonacci.py index 60cc667..16a03a4 100644 --- a/Sprint-2/improve_with_caches/fibonacci/fibonacci.py +++ b/Sprint-2/improve_with_caches/fibonacci/fibonacci.py @@ -1,4 +1,10 @@ +cache = {} + def fibonacci(n): if n <= 1: return n - return fibonacci(n - 1) + fibonacci(n - 2) + if n in cache: + return cache[n] + else: + cache[n] = fibonacci(n - 1) + fibonacci(n - 2) + return cache[n] 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..9b6d058 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 = [200, 100, 50, 20, 10, 5, 2, 1] +COINT_TYPES_NUM = len(COINS) def ways_to_make_change(total: int) -> int: """ @@ -7,26 +9,32 @@ 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, coin_index: int) -> int: """ Helper function for ways_to_make_change to avoid exposing the coins parameter to callers. """ - if total == 0 or len(coins) == 0: + if (total, coin_index) in cache: + return cache[(total, coin_index)] + + if total == 0: + return 1 + + if coin_index == COINT_TYPES_NUM: return 0 + 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 + coin = COINS[coin_index] + count_of_coin = 0 + while count_of_coin * coin <= total: + ways += ways_to_make_change_helper( + total - count_of_coin * coin, + coin_index + 1 + ) + count_of_coin += 1 + + cache[(total, coin_index)] = ways return ways From afcae8c5d28aa45b88add754da709ecfe18ada6e Mon Sep 17 00:00:00 2001 From: TarasMykytiuk Date: Sun, 28 Jun 2026 23:59:39 +0100 Subject: [PATCH 2/2] feedback fix 2 --- .../fibonacci/fibonacci.py | 6 ++--- .../making_change/making_change.py | 24 ++++++++++--------- 2 files changed, 15 insertions(+), 15 deletions(-) diff --git a/Sprint-2/improve_with_caches/fibonacci/fibonacci.py b/Sprint-2/improve_with_caches/fibonacci/fibonacci.py index 16a03a4..936d260 100644 --- a/Sprint-2/improve_with_caches/fibonacci/fibonacci.py +++ b/Sprint-2/improve_with_caches/fibonacci/fibonacci.py @@ -1,10 +1,8 @@ -cache = {} - -def fibonacci(n): +def fibonacci(n, cache = {}): if n <= 1: return n if n in cache: return cache[n] else: - cache[n] = fibonacci(n - 1) + fibonacci(n - 2) + cache[n] = fibonacci(n - 1, cache) + fibonacci(n - 2, cache) return cache[n] 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 9b6d058..9ea67e5 100644 --- a/Sprint-2/improve_with_caches/making_change/making_change.py +++ b/Sprint-2/improve_with_caches/making_change/making_change.py @@ -1,7 +1,4 @@ from typing import List -cache = {} -COINS = [200, 100, 50, 20, 10, 5, 2, 1] -COINT_TYPES_NUM = len(COINS) def ways_to_make_change(total: int) -> int: """ @@ -9,32 +6,37 @@ 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, 0) + coins = [200, 100, 50, 20, 10, 5, 2, 1] + return ways_to_make_change_helper(total, 0, coins) -def ways_to_make_change_helper(total: int, coin_index: int) -> int: +def ways_to_make_change_helper(total: int, coin_index: int, coins: List[int], cache = {}) -> int: """ Helper function for ways_to_make_change to avoid exposing the coins parameter to callers. """ - if (total, coin_index) in cache: - return cache[(total, coin_index)] + coins_types_num = len(coins) + index_total = (total, coin_index) + if index_total in cache: + return cache[index_total] if total == 0: return 1 - if coin_index == COINT_TYPES_NUM: + if coin_index == coins_types_num: return 0 ways = 0 - coin = COINS[coin_index] + coin = coins[coin_index] count_of_coin = 0 while count_of_coin * coin <= total: ways += ways_to_make_change_helper( total - count_of_coin * coin, - coin_index + 1 + coin_index + 1, + coins, + cache ) count_of_coin += 1 - cache[(total, coin_index)] = ways + cache[index_total] = ways return ways