From 7e20d44ff73e32bfea6d2055b37371bda400d191 Mon Sep 17 00:00:00 2001 From: Aida Eslami Date: Sun, 1 Mar 2026 19:29:20 +0000 Subject: [PATCH] add caching to improve performance --- .../fibonacci/fibonacci.py | 9 +++++- .../making_change/making_change.py | 29 +++++++++++-------- 2 files changed, 25 insertions(+), 13 deletions(-) diff --git a/Sprint-2/improve_with_caches/fibonacci/fibonacci.py b/Sprint-2/improve_with_caches/fibonacci/fibonacci.py index 60cc667..944b65c 100644 --- a/Sprint-2/improve_with_caches/fibonacci/fibonacci.py +++ b/Sprint-2/improve_with_caches/fibonacci/fibonacci.py @@ -1,4 +1,11 @@ +cache = {} + def fibonacci(n): if n <= 1: return n - return fibonacci(n - 1) + fibonacci(n - 2) + + if n in cache: + return cache[n] + + cache[n] = fibonacci(n - 1) + fibonacci(n - 2) + return cache[n] \ No newline at end of file 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..b469f8f 100644 --- a/Sprint-2/improve_with_caches/making_change/making_change.py +++ b/Sprint-2/improve_with_caches/making_change/making_change.py @@ -1,20 +1,21 @@ from typing import List +cache = {} 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. - """ return ways_to_make_change_helper(total, [200, 100, 50, 20, 10, 5, 2, 1]) def ways_to_make_change_helper(total: int, coins: List[int]) -> int: - """ - Helper function for ways_to_make_change to avoid exposing the coins parameter to callers. - """ - if total == 0 or len(coins) == 0: + key = (total, tuple(coins)) + + if key in cache: + return cache[key] + + if total == 0: + return 1 + + if total < 0 or len(coins) == 0: return 0 ways = 0 @@ -26,7 +27,11 @@ 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:]) - ways += intermediate + ways += ways_to_make_change_helper( + total - total_from_coins, + coins=coins[coin_index + 1:] + ) count_of_coin += 1 - return ways + + cache[key] = ways + return ways \ No newline at end of file