2019 day 7 part 1

2019/intcode/intcode.py

@@ -0,0 +1,132 @@
+#! /usr/bin/env python3
+from collections import namedtuple
+from enum import Enum
+import logging
+
+logging.basicConfig(format="%(levelname)s:%(message)s", level=logging.DEBUG)
+
+
+def get_nth_digit(n, number):
+    "Returns the nth digit of the input number"
+    return number // 10 ** n % 10
+
+
+class Operation(Enum):
+    ADDITION = 1
+    MULTIPLICATION = 2
+    INPUT = 3
+    OUTPUT = 4
+    JMP_IF_TRUE = 5
+    JMP_IF_FALSE = 6
+    LESS_THAN = 7
+    EQUALS = 8
+    TERMINATION = 99
+
+
+class Mode(Enum):
+    POSITION = 0
+    IMMEDIATE = 1
+
+
+class Instruction:
+    def __init__(self, opcode):
+        self.opcode = opcode
+        # A B C D E
+        # 0 1 1 0 3 
+        # A B C modes, DE opcode
+        self.operation = Operation(opcode % 100)
+        self.modes = [Mode(get_nth_digit(n, opcode)) for n in range(2, 5)]
+        self.handler_name = f"handle_{self.operation.name.lower()}"
+        self.handler = getattr(self, self.handler_name, self.handle_termination)
+        self.input = None
+        self.output = None
+
+    def __repr__(self):
+        return f"[{self.opcode}] Instruction({self.operation}, {self.modes})"
+
+    def handle(self, program, ip):
+        return self.handler(program, ip)
+
+    def handle_addition(self, program, ip):
+        first, second = self._get_parameters(program, ip)
+        logging.debug(f"ADD {first} {second}")
+        result = first + second
+        # the last mode should *always* be POSITION
+        program[program[ip + 3]] = result
+        ip += 4
+        return ip
+
+    def handle_multiplication(self, program, ip):
+        first, second = self._get_parameters(program, ip)
+        logging.debug(f"MUL {first} {second}")
+        result = first * second
+        # the last mode should *always* be POSITION
+        program[program[ip + 3]] = result
+        ip += 4
+        return ip
+
+    def handle_input(self, program, ip):
+        program[program[ip + 1]] = self.input
+        ip += 2
+        return ip
+
+    def handle_output(self, program, ip):
+        self.output = self._get_param(program, ip)
+        logging.debug(f"OUT {self.output}")
+        ip += 2
+        return ip
+
+    def handle_jmp_if_true(self, program, ip):
+        first, second = self._get_parameters(program, ip)
+        logging.debug(f"JMPT {first} {second}")
+        return second if first != 0 else ip + 3
+
+    def handle_jmp_if_false(self, program, ip):
+        first, second = self._get_parameters(program, ip)
+        logging.debug(f"JMPF {first} {second}")
+        return second if first == 0 else ip + 3
+
+    def handle_less_than(self, program, ip):
+        first, second = self._get_parameters(program, ip)
+        logging.debug(f"LT {first} {second}")
+        program[program[ip + 3]] = int(first < second)
+        ip += 4
+        return ip
+
+    def handle_equals(self, program, ip):
+        first, second = self._get_parameters(program, ip)
+        logging.debug(f"EQ {first} {second}")
+        program[program[ip + 3]] = int(first == second)
+        ip += 4
+        return ip
+
+    def handle_termination(self, program, ip):
+        logging.debug("HALT")
+        return ip
+
+    def _get_param(self, program, ip, i=0):
+        return (
+            program[ip + i + 1]
+            if self.modes[i] is Mode.IMMEDIATE
+            else program[program[ip + i + 1]]
+        )
+
+    def _get_parameters(self, program, ip):
+        first = self._get_param(program, ip, 0)
+        second = self._get_param(program, ip, 1)
+        return first, second
+
+
+def interpret_intcode(program, stdin=[]):
+    ip = 0
+    out = []
+    while program[ip] != 99:
+        opcode = program[ip]
+        instruction = Instruction(opcode)
+        if instruction.operation == Operation.INPUT:
+            instruction.input=stdin.pop(0)
+        ip = instruction.handle(program, ip)
+        if instruction.output is not None:
+            out.append(instruction.output)
+    return out
+