refactor: make COINS global variable

Author: JanefrancessC

Sprint-2/improve_with_caches/making_change/making_change.py

@@ -1,3 +1,5 @@
+COINS = (200, 100, 50, 20, 10, 5, 2, 1)
+
 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.
@@ -11,7 +13,6 @@ def ways_to_make_change_helper(total: int, coin_index: int, cache={}) -> int:
     """
     Helper function for ways_to_make_change to avoid exposing the coins parameter to callers.
     """
-    coins = (200, 100, 50, 20, 10, 5, 2, 1)
 
     key = (total, coin_index)
 
@@ -21,15 +22,16 @@ def ways_to_make_change_helper(total: int, coin_index: int, cache={}) -> int:
     if total == 0:
         return 1
 
-    if coin_index == len(coins):
+    if coin_index == len(COINS):
         return 0
 
-    coin = coins[coin_index]
+    coin = COINS[coin_index]
 
     if coin > total:
         ways = ways_to_make_change_helper(total, coin_index + 1)
+        
     else:
-        ways = (ways_to_make_change_helper(total - coin, coin_index) + ways_to_make_change_helper(total, coin_index + 1))
+        ways = (ways_to_make_change_helper(total - coin, coin_index)) + ways_to_make_change_helper(total, coin_index + 1)
 
     cache[key] = ways
     return ways