#7 Adding day07

costs = set()
for location in range(len(self.positions) + 1):
  costs.add(self.calc_fuel_pricey(location))
return min(costs)

costs = []
for location in range(len(self.positions) + 1):
  costs.append(self.calc_fuel_pricey(location))
return min(costs)                                                                                                                                                                                                                                                                                                                                             

I tried a few different functions setups for calculating the fuel with expensive. While using the set() and list methods seemed slightly faster, it likely uses quite a bit more memory on larger datasets (lists in particular). Tried: ``` costs = set() for location in range(len(self.positions) + 1): costs.add(self.calc_fuel_pricey(location)) return min(costs) ``` ``` costs = [] for location in range(len(self.positions) + 1): costs.append(self.calc_fuel_pricey(location)) return min(costs) ```