2019: d09: ex2: add solution

2019/d09/ex2/ex2.py

@@ -0,0 +1,211 @@
+#!/usr/bin/env python
+
+import itertools
+import sys
+from copy import deepcopy
+from dataclasses import dataclass, field
+from enum import IntEnum
+from typing import Callable, List, NamedTuple
+
+
+class ParameterMode(IntEnum):
+    POSITION = 0  # Acts on address
+    IMMEDIATE = 1  # Acts on the immediate value
+    RELATIVE = 2  # Acts on offset to relative base
+
+
+class Instruction(NamedTuple):
+    address: int  # The address of the instruction, for convenience
+    op: int  # The opcode
+    p1_mode: ParameterMode  # Which mode is the first parameter in
+    p2_mode: ParameterMode  # Which mode is the second parameter in
+    p3_mode: ParameterMode  # Which mode is the third parameter in
+
+
+def lookup_ops(index: int, memory: List[int]) -> Instruction:
+    digits = list(map(int, str(memory[index])))
+    a, b, c, d, e = [0] * (5 - len(digits)) + digits  # Pad with default values
+    return Instruction(
+        address=index,
+        op=d * 10 + e,
+        p1_mode=ParameterMode(c),
+        p2_mode=ParameterMode(b),
+        p3_mode=ParameterMode(a),
+    )
+
+
+class InputInterrupt(Exception):
+    pass
+
+
+class OutputInterrupt(Exception):
+    pass
+
+
+@dataclass
+class Computer:
+    memory: List[int]  # Memory space
+    rip: int = 0  # Instruction pointer
+    input_list: List[int] = field(default_factory=list)
+    output_list: List[int] = field(default_factory=list)
+    is_halted: bool = field(default=False, init=False)
+    relative_base: int = field(default=0, init=False)
+
+    def run(self) -> None:
+        while not self.is_halted:
+            self.run_single()
+
+    def run_no_output_interrupt(self) -> None:
+        while not self.is_halted:
+            try:
+                self.run_single()
+            except OutputInterrupt:
+                continue
+
+    def run_single(self):  # Returns True when halted
+        instr = lookup_ops(self.rip, self.memory)
+        if instr.op == 99:  # Halt
+            self.is_halted = True
+        elif instr.op == 1:  # Sum
+            self._do_addition(instr)
+        elif instr.op == 2:  # Multiplication
+            self._do_multiplication(instr)
+        elif instr.op == 3:  # Load from input
+            self._do_input(instr)
+        elif instr.op == 4:  # Store to output
+            self._do_output(instr)
+        elif instr.op == 5:  # Jump if true
+            self._do_jump_if_true(instr)
+        elif instr.op == 6:  # Jump if false
+            self._do_jump_if_false(instr)
+        elif instr.op == 7:  # Less than
+            self._do_less_than(instr)
+        elif instr.op == 8:  # Equal to
+            self._do_equal_to(instr)
+        elif instr.op == 9:  # Change relative base
+            self._do_change_relative_base(instr)
+        else:
+            assert False  # Sanity check
+
+    def _fill_to_addres(self, address: int) -> None:
+        values = address - len(self.memory) + 1
+        if values <= 0:
+            return
+        for __ in range(values):
+            self.memory.append(0)
+
+    def _get_value(self, mode: ParameterMode, val: int) -> int:
+        if mode == ParameterMode.POSITION:
+            assert 0 <= val  # Sanity check
+            self._fill_to_addres(val)
+            return self.memory[val]
+        elif mode == ParameterMode.RELATIVE:
+            val += self.relative_base
+            assert 0 <= val  # Sanity check
+            self._fill_to_addres(val)
+            return self.memory[val]
+        assert mode == ParameterMode.IMMEDIATE  # Sanity check
+        return val
+
+    def _set_value(self, mode: ParameterMode, address: int, value: int) -> None:
+        if mode == ParameterMode.RELATIVE:
+            address += self.relative_base
+        else:
+            assert mode == ParameterMode.POSITION  # Sanity check
+
+        assert address >= 0  # Sanity check
+        self._fill_to_addres(address)
+
+        self.memory[address] = value
+
+    def _do_addition(self, instr: Instruction) -> None:
+        lhs = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
+        rhs = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
+        dest = self.memory[instr.address + 3]
+
+        self._set_value(instr.p3_mode, dest, lhs + rhs)
+
+        self.rip += 4  # Length of the instruction
+
+    def _do_multiplication(self, instr: Instruction) -> None:
+        lhs = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
+        rhs = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
+        dest = self.memory[instr.address + 3]
+
+        self._set_value(instr.p3_mode, dest, lhs * rhs)
+
+        self.rip += 4  # Length of the instruction
+
+    def _do_input(self, instr: Instruction) -> None:
+        if len(self.input_list) == 0:
+            raise InputInterrupt  # No input, halt until an input is provided
+
+        value = int(self.input_list.pop(0))
+        param = self.memory[instr.address + 1]
+
+        self._set_value(instr.p1_mode, param, value)
+
+        self.rip += 2  # Length of the instruction
+
+    def _do_output(self, instr: Instruction) -> None:
+        value = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
+
+        self.output_list.append(value)
+
+        self.rip += 2  # Length of the instruction
+        raise OutputInterrupt  # Alert that we got an output to give
+
+    def _do_jump_if_true(self, instr: Instruction) -> None:
+        cond = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
+        value = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
+
+        if cond != 0:
+            self.rip = value
+        else:
+            self.rip += 3  # Length of the instruction
+
+    def _do_jump_if_false(self, instr: Instruction) -> None:
+        cond = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
+        value = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
+
+        if cond == 0:
+            self.rip = value
+        else:
+            self.rip += 3  # Length of the instruction
+
+    def _do_less_than(self, instr: Instruction) -> None:
+        lhs = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
+        rhs = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
+        dest = self.memory[instr.address + 3]
+
+        self._set_value(instr.p3_mode, dest, 1 if lhs < rhs else 0)
+
+        self.rip += 4  # Length of the instruction
+
+    def _do_equal_to(self, instr: Instruction) -> None:
+        lhs = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
+        rhs = self._get_value(instr.p2_mode, self.memory[instr.address + 2])
+        dest = self.memory[instr.address + 3]
+
+        self._set_value(instr.p3_mode, dest, 1 if lhs == rhs else 0)
+
+        self.rip += 4  # Length of the instruction
+
+    def _do_change_relative_base(self, instr: Instruction) -> None:
+        value = self._get_value(instr.p1_mode, self.memory[instr.address + 1])
+
+        self.relative_base += value
+        self.rip += 2  # Length of the instruction
+
+
+def main() -> None:
+    memory = [int(n) for n in sys.stdin.read().split(",")]
+    computer = Computer(deepcopy(memory), input_list=[2])
+
+    computer.run_no_output_interrupt()
+    print(computer.output_list.pop())
+    assert len(computer.output_list) == 0  # Sanity check
+
+
+if __name__ == "__main__":
+    main()