Day 21 Python solutions

Author: creideiki

21-1.py

@@ -0,0 +1,50 @@
+#!/usr/bin/env python
+
+import re
+
+monkeys = {}
+
+class Monkey:
+    def __init__(self, name, operation):
+        number_format = re.compile("^(?P<num>[0-9]+)$")
+        calc_format = re.compile("^(?P<m1>[a-z]+) (?P<op>[-+*/]) (?P<m2>[a-z]+)$")
+
+        self.operation = operation
+        self.name = name
+        self.val = None
+        if (m := number_format.match(self.operation)):
+            self.val = int(m["num"])
+        else:
+            m = calc_format.match(self.operation)
+            self.m1 = m["m1"]
+            self.op = m["op"]
+            self.m2 = m["m2"]
+
+    def value(self):
+        if self.val is not None:
+            return self.val
+
+        if self.op == "+":
+            self.val = monkeys[self.m1].value() + monkeys[self.m2].value()
+        elif self.op == "-":
+            self.val = monkeys[self.m1].value() - monkeys[self.m2].value()
+        elif self.op == "*":
+            self.val = monkeys[self.m1].value() * monkeys[self.m2].value()
+        elif self.op == "/":
+            self.val = monkeys[self.m1].value() // monkeys[self.m2].value()
+
+        return self.val
+
+    def __str__(self):
+        return f"<{self.__class__.__name__}: {self.name} = {self.operation} ({self.val})>"
+
+
+monkey_format = re.compile("^(?P<name>[a-z]+): (?P<op>.*)$")
+
+lines = [row.strip() for row in open("21.input").readlines()]
+
+for line in lines:
+    m = monkey_format.match(line)
+    monkeys[m["name"]] = Monkey(m["name"], m["op"])
+
+print(monkeys["root"].value())

21-2.py

@@ -0,0 +1,105 @@
+#!/usr/bin/env python
+
+import re
+
+monkeys = {}
+
+class IsHuman(RuntimeError):
+    pass
+
+class Monkey:
+    setting = False
+
+    def __init__(self, name, operation):
+        number_format = re.compile("^(?P<num>[0-9]+)$")
+        calc_format = re.compile("^(?P<m1>[a-z]+) (?P<op>[-+*/]) (?P<m2>[a-z]+)$")
+
+        self.operation = operation
+        self.name = name
+        self.val = None
+        if (m := number_format.match(self.operation)):
+            self.val = int(m["num"])
+        else:
+            m = calc_format.match(self.operation)
+            self.m1 = m["m1"]
+            self.op = m["op"]
+            if self.name == "root":
+                self.op = "=="
+            self.m2 = m["m2"]
+
+    def value(self):
+        if self.setting and self.name == "humn":
+            raise IsHuman
+
+        if self.val is not None:
+            return self.val
+
+        if self.op == "+":
+            self.val = monkeys[self.m1].value() + monkeys[self.m2].value()
+        elif self.op == "-":
+            self.val = monkeys[self.m1].value() - monkeys[self.m2].value()
+        elif self.op == "*":
+            self.val = monkeys[self.m1].value() * monkeys[self.m2].value()
+        elif self.op == "/":
+            self.val = monkeys[self.m1].value() // monkeys[self.m2].value()
+
+        return self.val
+
+    def set_equal(self, value):
+        if self.name == "humn":
+            self.val = value
+            return
+
+        try:
+            left = monkeys[self.m1].value()
+        except IsHuman:
+            left = None
+
+        try:
+            right = monkeys[self.m2].value()
+        except IsHuman:
+            right = None
+
+        if self.op == "==":
+            if right is not None:
+                monkeys[self.m1].set_equal(right)
+            if left is not None:
+                monkeys[self.m2].set_equal(left)
+        elif self.op == "+":
+            if right is not None:
+                monkeys[self.m1].set_equal(value - right)
+            if left is not None:
+                monkeys[self.m2].set_equal(value - left)
+        elif self.op == "-":
+            if right is not None:
+                monkeys[self.m1].set_equal(value + right)
+            if left is not None:
+                monkeys[self.m2].set_equal(left - value)
+        elif self.op == "*":
+            if right is not None:
+                monkeys[self.m1].set_equal(value // right)
+            if left is not None:
+                monkeys[self.m2].set_equal(value // left)
+        elif self.op == "/":
+            if right is not None:
+                monkeys[self.m1].set_equal(value * right)
+            if left is not None:
+                monkeys[self.m2].set_equal(left // value)
+
+    def __str__(self):
+        return f"<{self.__class__.__name__}: {self.name} = {self.operation} ({self.val})>"
+
+
+monkey_format = re.compile("^(?P<name>[a-z]+): (?P<op>.*)$")
+
+lines = [row.strip() for row in open("21.input").readlines()]
+
+for line in lines:
+    m = monkey_format.match(line)
+    monkeys[m["name"]] = Monkey(m["name"], m["op"])
+
+Monkey.setting = True
+monkeys["root"].set_equal(None)
+Monkey.setting = False
+
+print(monkeys["humn"].value())