4 files changed, 2879 insertions, 2 deletions

diff --git a/aoc/decorators.py b/aoc/decorators.py
index a31993a..42603c2 100644
--- a/aoc/decorators.py
+++ b/aoc/decorators.py
@@ -1,11 +1,15 @@
 # -*- coding: utf-8 -*-
 from functools import wraps
-from typing import Iterator, TypeVar, Callable
+from typing import Iterator, TypeVar, Callable, List
 
 T = TypeVar("T")
+I = TypeVar("I")
 
+AssignmentRun = Callable[[Iterator[I], ...], Iterator[T]]
+AssignmentRunList = Callable[[List[I], ...], Iterator[T]]
 
-def infinite_generator(func: Callable[[...], Iterator[T]]):
+
+def infinite_generator(func: AssignmentRun) -> AssignmentRun:
     @wraps(func)
     def wrapper(*args, **kwargs):
         items = list(func(*args, **kwargs))
@@ -15,3 +19,12 @@ def infinite_generator(func: Callable[[...], Iterator[T]]):
                 yield item
 
     return wrapper
+
+
+def list_input(func: AssignmentRun) -> AssignmentRunList:
+    @wraps(func)
+    def wrapper(self, input: Iterator, *args, **kwargs) -> T:
+
+        return func(self, list(input), *args, **kwargs)
+
+    return wrapper
diff --git a/day21/__init__.py b/day21/__init__.py
new file mode 100644
index 0000000..23fd520
--- /dev/null
+++ b/day21/__init__.py
@@ -0,0 +1,122 @@
+# -*- coding: utf-8 -*-
+from abc import ABC
+from typing import Dict, Union, Iterator, Type, Callable, List
+from operator import add, sub, mul, truediv, eq, floordiv
+
+from aoc import BaseAssignment
+from aoc.decorators import list_input
+from aoc.mixins import AStarMixin
+
+
+class MonkeyActivity:
+    def __init__(self, name: str, monkeys: Dict[str, "MonkeyActivity"]):
+        self.name = name
+        self.monkeys = monkeys
+        self.monkeys[name] = self
+
+    def __repr__(self):
+        return f"{self.name}"
+
+    @property
+    def value(self) -> int:
+        raise NotImplementedError()
+
+
+class Yell(MonkeyActivity):
+    def __init__(self, value: str, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        self._value = int(value)
+
+    @property
+    def value(self) -> int:
+        return self._value
+
+
+class Operate(MonkeyActivity):
+    def __init__(self, a: str, b: str, operator: str, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        self.operator = operator
+        self._a = a
+        self._b = b
+        self._operator = {
+            "+": add,
+            "-": sub,
+            "*": mul,
+            "/": truediv,
+        }[operator]
+
+    @property
+    def a(self) -> MonkeyActivity:
+        return self.monkeys[self._a]
+
+    @property
+    def b(self) -> MonkeyActivity:
+        return self.monkeys[self._b]
+
+    @property
+    def value(self) -> int:
+        return int(self._operator(self.a.value, self.b.value))
+
+
+class Assignment(BaseAssignment[int, MonkeyActivity], ABC):
+    monkeys = {}
+
+    def parse_item(self, item: str) -> MonkeyActivity:
+        name, activity = item.split(": ")
+        activity = activity.split(" ")
+
+        if len(activity) == 1:
+            return Yell(*activity, name, self.monkeys)
+
+        a, operator, b = activity
+
+        return Operate(a, b, operator, name, self.monkeys)
+
+
+class AssignmentOne(Assignment):
+    example_result = 152
+
+    @list_input
+    def run(self, _: List[MonkeyActivity]) -> int:
+        return self.monkeys["root"].value
+
+
+class AssignmentTwo(Assignment, AStarMixin[MonkeyActivity]):
+    example_result = 301
+
+    @staticmethod
+    def neighbours(node: MonkeyActivity):
+        if isinstance(node, Operate):
+            yield node.a
+            yield node.b
+
+    @list_input
+    def run(self, _: List[MonkeyActivity]) -> int:
+        root = self.monkeys["root"]
+        humn = self.monkeys["humn"]
+        humn._value = 0
+
+        path = self.a_star(
+            root,
+            lambda n, _: n is humn,
+            self.neighbours,
+        )
+
+        for item in path:
+            if isinstance(item, Yell):
+                break
+
+            item: Operate = item
+            reverse_operator = {
+                "+": sub,
+                "-": add,
+                "*": floordiv,
+                "/": mul,
+            }[item.operator]
+
+            humn._value = reverse_operator(item.b.value, item.a.value)
+            pass
+
+        return humn._value
diff --git a/day21/example.txt b/day21/example.txt
new file mode 100644
index 0000000..e14be60
--- /dev/null
+++ b/day21/example.txt
@@ -0,0 +1,15 @@
+root: pppw + sjmn
+dbpl: 5
+cczh: sllz + lgvd
+zczc: 2
+ptdq: humn - dvpt
+dvpt: 3
+lfqf: 4
+humn: 5
+ljgn: 2
+sjmn: drzm * dbpl
+sllz: 4
+pppw: cczh / lfqf
+lgvd: ljgn * ptdq
+drzm: hmdt - zczc
+hmdt: 32
diff --git a/day21/input.txt b/day21/input.txt
new file mode 100644
index 0000000..0696184
--- /dev/null
+++ b/day21/input.txt
@@ -0,0 +1,2727 @@
+cjdb: 3
+hhfs: 5
+jvjn: 4
+tjzm: bngm * mrfm
+mbbs: 2
+dzlq: tcdz * bjdj
+htzp: 3
+hsmn: 5
+sblh: 2
+pghw: 5
+pqtp: vtcr * bcts
+mvgz: 2
+sszn: 3
+zqlr: nlfq * htfq
+djsb: 2
+vccw: zzsz * thbz
+tlvg: fncr + glvj
+grql: nqch * jhmw
+rngv: 4
+prjv: 2
+rmdl: lzdr * qpzh
+pdqm: 2
+jrpn: zcnv + pgqr
+llzf: 2
+bzfp: qbwz + zsts
+bvsf: rbcd + npcs
+jmpm: 3
+zgrs: 15
+lcrs: 5
+cqcc: swtj + wnzt
+vhts: 2
+pbgz: 1
+mqpb: 2
+jzcf: 2
+sfls: 10
+cnhh: 8
+clsh: mcwb * jfrq
+cqch: 4
+brvd: 19
+fprh: 2
+dccm: gbhn / tczb
+wmgt: ldsd + csmf
+hbrs: 6
+bjqq: 12
+pvnl: 6
+htdg: 2
+tpcm: hfdz * sfrt
+sgcj: slfv * wzdf
+fljs: 2
+qmml: 2
+sbqt: 2
+wjqn: 4
+fmzj: 1
+dnwt: 18
+dzld: rvhr * jfjj
+qnfn: mrhp * wlhj
+sccz: 3
+lbcv: hqjn + lhcg
+bwdw: 16
+jmgq: czzm * sjqr
+zqnd: fhfm + sstq
+mlwd: 3
+mpnz: vdqm * ccgq
+bcsn: cmrp * prhj
+gsvq: cqcc / twjg
+zcgv: 4
+sjvd: cvsz * zdmr
+fzwf: 5
+cdpv: 1
+ndcq: 4
+mvps: 2
+twsv: qfsn * pmrb
+gglt: nlnl * cjdb
+pvnm: 1
+wcfh: 7