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, position):
 23        self._position = position
 24
 25    def distance_to(self, other):
 26        return math.sqrt((self._position[0] - other._position[0])**2 
 27                         + (self._position[1] - other._position[1])**2)
 28
 29
 30class Kid(Person):
 31
 32    MAX_CANDIES = 20
 33
 34    def __init__(self, position, initiative):
 35        super().__init__(position)
 36        self._initiative = initiative
 37        self._visited_hosts = set()
 38        self._candies = set()
 39        self._uranium_in_basket = 0
 40
 41    def get_initiative(self):
 42        return self._initiative
 43    
 44    def add_candy(self, candy):
 45        self._uranium_in_basket += candy.get_uranium_quantity()
 46        self._candies.add(candy)
 47
 48    def is_critical(self):
 49        if self._uranium_in_basket > self.MAX_CANDIES:
 50            return True
 51        return False
 52    
 53    def visit(self, host):
 54        self._visited_hosts.add(host)
 55        self.set_position(host.get_position())
 56
 57    def has_visited(self, host):
 58        return host in self._visited_hosts
 59    
 60
 61class Host(Person):
 62    def __init__(self, position, candies):
 63        super().__init__(position)
 64        self._candies = []
 65        self._visitors = []
 66        for candy in candies:
 67            self._candies.append(Candy(*candy))
 68
 69    def remove_candy(self, pick_candy_func):
 70        if not self._candies:
 71            return None
 72        candy = pick_candy_func(self._candies)
 73        self._candies.remove(candy)
 74        return candy
 75        
 76    def accept_visitor(self, kid):
 77        self._visitors.append(kid)
 78
 79    def get_compare_list(self, kid):
 80        return [
 81            kid.distance_to(self),
 82            self._position[0],
 83            self._position[1],
 84            self
 85        ]
 86
 87    def give_out_candies(self, pick_candy_func):
 88        self._visitors.sort(key=lambda kid: kid.get_initiative())
 89        while self._visitors:
 90            kid = self._visitors.pop()
 91            candy = self.remove_candy(pick_candy_func)
 92            if candy is not None:
 93                kid.add_candy(candy)
 94
 95        
 96class FluxCapacitor:
 97    def __init__(self, participants):
 98        self._kids = []
 99        self._hosts = []
100        self._victims = set()
101        for participant in participants:
102            if type(participant) is Kid:
103                self._kids.append(participant)
104            if type(participant) is Host:
105                self._hosts.append(participant)
106
107    def get_victim(self):
108        kids_who_visited_all = set()
109        while (len(kids_who_visited_all) != len(self._kids) 
110               and not self._victims):
111            for kid in self._kids:
112                if kid in kids_who_visited_all:
113                    continue
114                closest_host = self._get_closest_host(kid)
115                if closest_host is None:
116                    kids_who_visited_all.add(kid)
117                    continue
118                kid.visit(closest_host)
119                closest_host.accept_visitor(kid)
120            for host in self._hosts:
121                host.give_out_candies(self._pick_candy)
122            for kid in self._kids:
123                if kid.is_critical():
124                    self._victims.add(kid)
125        return self._victims or None
126    
127    def _get_closest_host(self, kid):
128        closest_host = [None]
129        for host in self._hosts:
130            if kid.has_visited(host):
131                continue
132            if None in closest_host:
133                closest_host = host.get_compare_list(kid)
134                continue
135            closest_host = min(closest_host, host.get_compare_list(kid))
136        return closest_host[-1]
137    
138    def _pick_candy(self, candies):
139        return max(candies, key=(lambda candy: candy.get_mass()))