Solve 2017/08

2017/08/solve.py

@@ -0,0 +1,96 @@
+import collections
+import re
+import sys
+
+# PART 1
+
+class Instruction:
+	INSTRUCTION_RE = r"(\S+) (inc|dec) (-?\d+) if (\S+) (<|<=|>|>=|==|!=) (-?\d+)\n"
+
+	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_file(cls, filename):
+		instructions = []
+
+		with open(filename, "r") as f:
+			for line in f:
+				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 main(filename):
+	print(f"Solutions for {filename}")
+	machine = Machine.from_file(filename)
+	machine.reset()
+	machine.execute()
+	max_register = machine.max_register()
+	print(f"Part 1: {max_register}")
+	print(f"Part 2: {machine.max_all_time}")
+
+if __name__ == "__main__":
+	for filename in sys.argv[1:]:
+		main(filename)

2017/08/test_input.txt

@@ -0,0 +1,4 @@
+b inc 5 if a > 1
+a inc 1 if b < 5
+c dec -10 if a >= 1
+c inc -20 if c == 10