Speeding up the cost search

puzzles/day07.py

@@ -20,7 +20,7 @@ class AlignCrabSubs:
     def calc_fuel(self, pricey: bool = False) -> int:
         if pricey:
             fuel = None
-            for position in range(len(self.positions) + 1):
+            for position in range(len(set(self.positions)) + 1):
                 price = self.calc_fuel_pricey(position)
                 if fuel is None or fuel > price:
                     fuel = price