Python: book_store

python/book-store/book_store.py

@@ -0,0 +1,33 @@
+from collections import Counter
+from itertools import combinations
+
+DISCOUNTS = [0, 0, 5, 10, 20, 25]
+BOOK_COST = 8
+
+
+def get_discount(counter):
+
+    xs = sorted([i for i in counter if i != 0], reverse=True)
+
+    if not xs:
+        return 0
+
+    discount = 0
+
+    for group_size in range(1, len(xs) + 1):
+        for xs1 in combinations(xs, len(xs)):
+            xs1 = [item - 1 if index < group_size else item
+                   for index, item in enumerate(xs1)]
+            curr_discount = (
+                DISCOUNTS[group_size]*group_size + get_discount(xs1)
+            )
+            if curr_discount > discount:
+                discount = curr_discount
+
+    return discount
+
+
+def total(basket):
+
+    return BOOK_COST*(len(basket)*100
+                      - get_discount(Counter(basket).values()))