[py] Port 2017_08

py/aoc/y2017/d08.py

@@ -0,0 +1,93 @@
+import collections
+import re
+
+# PART 1
+
+
+class Instruction:
+    INSTRUCTION_RE = r"(\S+) (inc|dec) (-?\d+) if (\S+) (<|<=|>|>=|==|!=) (-?\d+)"
+
+    def __init__(self, register, mode, amount, c_register, c_operator, c_amount):
+        self.register = register
+        self.mode = mode
+        self.amount = amount
+        self.c_register = c_register
+        self.c_operator = c_operator
+        self.c_amount = c_amount
+
+    @classmethod
+    def from_line(cls, line):
+        match = re.fullmatch(cls.INSTRUCTION_RE, line)
+
+        register = match.group(1)
+        mode = match.group(2)
+        amount = int(match.group(3))
+        c_register = match.group(4)
+        c_operator = match.group(5)
+        c_amount = int(match.group(6))
+
+        return cls(register, mode, amount, c_register, c_operator, c_amount)
+
+    def compare_to(self, n):
+        if self.c_operator == "<":
+            return n < self.c_amount
+        elif self.c_operator == "<=":
+            return n <= self.c_amount
+        elif self.c_operator == ">":
+            return n > self.c_amount
+        elif self.c_operator == ">=":
+            return n >= self.c_amount
+        elif self.c_operator == "==":
+            return n == self.c_amount
+        elif self.c_operator == "!=":
+            return n != self.c_amount
+
+    def total(self):
+        if self.mode == "inc":
+            return self.amount
+        elif self.mode == "dec":
+            return -self.amount
+
+
+class Machine:
+    def __init__(self, instructions):
+        self.instructions = instructions
+        self.reset()
+
+    def reset(self):
+        self.registers = collections.defaultdict(lambda: 0)
+        self.max_all_time = 0
+
+    @classmethod
+    def from_str(cls, s):
+        instructions = []
+
+        for line in s.splitlines():
+            instructions.append(Instruction.from_line(line))
+
+        return cls(instructions)
+
+    def execute_instruction(self, i):
+        c_amount = self.registers.get(i.c_register, 0)
+        if i.compare_to(c_amount):
+            self.registers[i.register] += i.total()
+            self.max_all_time = max(self.max_all_time, self.registers[i.register])
+
+    def execute(self):
+        for i in self.instructions:
+            self.execute_instruction(i)
+
+    def max_register(self):
+        return max(self.registers.values())
+
+
+# PART 2
+
+
+def solve(inputstr):
+    machine = Machine.from_str(inputstr)
+    machine.reset()
+    machine.execute()
+    max_register = machine.max_register()
+    print(f"Part 1: {max_register}")
+    print(f"Part 2: {machine.max_all_time}")