run length encoding exercise

python/book-store/book_store.py

@@ -0,0 +1,14 @@
+from itertools import combinations_with_replacement
+PRICES = {1: 8, 2: 16 * 0.95, 3: 24 * 0.90, 4: 32 * 0.80, 5: 40 * 0.75}
+
+
+def total(books):
+    num_books = len(books)
+    unique = len(set(books))
+    counts = [books.count(book) for book in books]
+    try:
+        combos = combinations_with_replacement(range(1, unique+1), max(counts))
+    except ValueError:
+        return 0.00
+    combos = (combo for combo in combos if sum(combo) == num_books)
+    return round(min(sum(PRICES[c] for c in combo) for combo in combos)*100)