1import math
 2
 3class Candy:
 4    def __init__(self, mass, uranium):
 5        self.mass = mass
 6        self.uranium = uranium
 7
 8    def get_uranium_quantity(self):
 9        return self.mass * self.uranium
10
11    def get_mass(self):
12        return self.mass
13
14
15class Person:
16    def __init__(self, position):
17        self.position = position
18
19    def get_position(self):
20        return self.position
21
22    def set_position(self, new_position):
23        self.position = new_position
24
25
26class Kid(Person):
27    CRITICAL_URANIUM_MASS = 20
28
29    def __init__(self, position, initiative):
30        super().__init__(position)
31        self.initiative = initiative
32        self.candies = []
33
34    def get_initiative(self):
35        return self.initiative
36
37    def add_candy(self, candy):
38        self.candies.append(candy)
39
40    def is_critical(self):
41        uranium_mass = sum(candy.get_uranium_quantity() for candy in self.candies)
42        return uranium_mass > Kid.CRITICAL_URANIUM_MASS
43    
44    def move_to_host(self, host):
45        self.set_position(host.get_position())
46
47
48class Host(Person):
49    def __init__(self, position, candies):
50        super().__init__(position)
51        self.candies = [Candy(mass, uranium) for mass, uranium in candies]
52
53    def remove_candy(self, selection_function):
54        if not self.candies:
55            return None
56        selected_candy = selection_function(self.candies)
57        self.candies.remove(selected_candy)
58        return selected_candy
59
60
61class FluxCapacitor:
62    def __init__(self, participants):
63        self.kids = {p for p in participants if isinstance(p, Kid)}
64        self.hosts = {p for p in participants if isinstance(p, Host)}
65        self.victims = set()
66        self.simulate_halloween()
67
68    def get_victim(self):
69        return self.victims if self.victims else None
70
71    def simulate_halloween(self):
72        visited_hosts = {kid: set() for kid in self.kids}
73        while self.hosts and not self.victims:
74            for kid in sorted(self.kids, key=lambda k: k.get_initiative(), reverse=True):
75                closest_host = self.find_closest_host(kid, visited_hosts[kid])
76                if closest_host:
77                    visited_hosts[kid].add(closest_host)
78                    kid.move_to_host(closest_host)
79                    candy = closest_host.remove_candy(lambda candies: max(candies, key=lambda c: c.get_mass()))
80                    if candy:
81                        kid.add_candy(candy)
82            self.victims = {kid for kid in self.kids if kid.is_critical()}
83            if self.victims:
84                break
85            self.hosts = {host for host in self.hosts if host.candies}
86            if not any(visited_hosts[kid] != self.hosts for kid in self.kids):
87                break
88
89    def find_closest_host(self, kid, visited_hosts):
90        unvisited_hosts = [(host, self.calculate_distance(kid.get_position(), host.get_position()))
91                           for host in self.hosts if host not in visited_hosts]
92        unvisited_hosts.sort(key=lambda x: (x[1], x[0].get_position()))
93        return unvisited_hosts[0][0] if unvisited_hosts else None
94
95    def calculate_distance(self, position1, position2):
96        return ((position1[0] - position2[0]) ** 2 + (position1[1] - position2[1]) ** 2) ** 0.5