From 8905e629ace764daea4cd10f2b4cd1d2a1ba2aa5 Mon Sep 17 00:00:00 2001 From: Alaa Date: Sat, 18 Oct 2025 10:04:47 +0100 Subject: [PATCH 1/3] Improve fibonacci caching --- Sprint-2/improve_with_caches/fibonacci/fibonacci.py | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/Sprint-2/improve_with_caches/fibonacci/fibonacci.py b/Sprint-2/improve_with_caches/fibonacci/fibonacci.py index 60cc667..ccceec1 100644 --- a/Sprint-2/improve_with_caches/fibonacci/fibonacci.py +++ b/Sprint-2/improve_with_caches/fibonacci/fibonacci.py @@ -1,4 +1,13 @@ +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 From 8b092d98ec800c44f1d7c2f06708c2e18db5c5b3 Mon Sep 17 00:00:00 2001 From: Alaa Date: Sat, 18 Oct 2025 10:05:48 +0100 Subject: [PATCH 2/3] Improve making change caching --- .../making_change/making_change.py | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) 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..f2de728 100644 --- a/Sprint-2/improve_with_caches/making_change/making_change.py +++ b/Sprint-2/improve_with_caches/making_change/making_change.py @@ -7,16 +7,24 @@ 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]) + # Cache to store computed results + cache = {} + return ways_to_make_change_helper(total, [200, 100, 50, 20, 10, 5, 2, 1], cache) -def ways_to_make_change_helper(total: int, coins: List[int]) -> int: +def ways_to_make_change_helper(total: int, coins: List[int], cache: dict) -> int: """ Helper function for ways_to_make_change to avoid exposing the coins parameter to callers. """ if total == 0 or len(coins) == 0: return 0 + # Create cache key from current state + cache_key = (total, tuple(coins)) + + if cache_key in cache: + return cache[cache_key] + ways = 0 for coin_index in range(len(coins)): coin = coins[coin_index] @@ -26,7 +34,10 @@ def ways_to_make_change_helper(total: int, coins: List[int]) -> int: if total_from_coins == total: ways += 1 else: - intermediate = ways_to_make_change_helper(total - total_from_coins, coins=coins[coin_index+1:]) + intermediate = ways_to_make_change_helper(total - total_from_coins, coins=coins[coin_index+1:], cache=cache) ways += intermediate count_of_coin += 1 + + # Store result in cache + cache[cache_key] = ways return ways From d79042c218ef96590447a898dbaf9a3071a3d6ac Mon Sep 17 00:00:00 2001 From: Alaa Date: Tue, 27 Jan 2026 10:53:09 +0000 Subject: [PATCH 3/3] refactor: optimize making_change to use tuple with index parameter --- .../making_change/making_change.py | 21 +++++++------------ 1 file changed, 8 insertions(+), 13 deletions(-) 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 f2de728..0acf3b4 100644 --- a/Sprint-2/improve_with_caches/making_change/making_change.py +++ b/Sprint-2/improve_with_caches/making_change/making_change.py @@ -1,43 +1,38 @@ -from typing import List - - def ways_to_make_change(total: int) -> int: """ Given access to coins with the values 1, 2, 5, 10, 20, 50, 100, 200, returns a count of all of the ways to make the passed total value. 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. """ - # Cache to store computed results cache = {} - return ways_to_make_change_helper(total, [200, 100, 50, 20, 10, 5, 2, 1], cache) + coins = (200, 100, 50, 20, 10, 5, 2, 1) + return ways_to_make_change_helper(total, coins, 0, cache) -def ways_to_make_change_helper(total: int, coins: List[int], cache: dict) -> int: +def ways_to_make_change_helper(total: int, coins: tuple, coin_index: int, cache: dict) -> 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 == 0 or coin_index >= len(coins): return 0 - # Create cache key from current state - cache_key = (total, tuple(coins)) + cache_key = (total, coin_index) if cache_key in cache: return cache[cache_key] ways = 0 - for coin_index in range(len(coins)): - coin = coins[coin_index] + for i in range(coin_index, len(coins)): + coin = coins[i] 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:], cache=cache) + intermediate = ways_to_make_change_helper(total - total_from_coins, coins, i + 1, cache) ways += intermediate count_of_coin += 1 - # Store result in cache cache[cache_key] = ways return ways