Implement brute force for 2019 day 25

2019/aoc2019/day25.py

@@ -1,9 +1,15 @@
-from typing import TextIO
+import itertools
+from typing import TextIO, Iterable, Tuple, Set
 
 from aoc2019.intcode import read_program, Computer
 
 
-def print_output(computer: Computer):
+def powerset(iterable: Iterable) -> Iterable[Tuple]:
+    s = list(iterable)
+    return itertools.chain.from_iterable(itertools.combinations(s, r) for r in range(len(s) + 1))
+
+
+def print_output(computer: Computer) -> str:
     output = ""
 
     while len(computer.output):
@@ -11,6 +17,8 @@ def print_output(computer: Computer):
 
     print(output, end='')
 
+    return output
+
 
 def load_save(save, computer: Computer):
     computer.pointer, computer.relative_base, computer.program = save
@@ -20,10 +28,40 @@ def create_save(computer: Computer):
     return computer.pointer, computer.relative_base, computer.program.copy()
 
 
+def send_command(computer: Computer, command: str):
+    for c in command:
+        computer.send_input(ord(c))
+
+    computer.send_input(10)  # manually send newline
+
+
+def force(computer: Computer, direction: str, items: Set[str]):
+    for combination in powerset(items):
+        # Drop everything, disregard what's on the ground
+        for item in items:
+            send_command(computer, f"drop {item}")
+
+        # Now pick up whatever we want to try
+        for item in combination:
+            send_command(computer, f"take {item}")
+
+        send_command(computer, direction)
+
+        try:
+            computer.run()
+            print_output(computer)
+            return True
+        except IndexError:
+            print_output(computer)
+
+    return False
+
+
 def part1(data: TextIO):
     print("This day must use a file as input as it requires the stdin for other things.")
 
     computer = Computer(read_program(data))
+    items = set()
 
     saves = {}
 
@@ -42,14 +80,35 @@ def part1(data: TextIO):
 
         saves['auto'] = create_save(computer)
 
+        try:
             command = input().strip()
+        except EOFError:
+            return "exiting"
 
         if command == "exit":
+            return "exiting"
+        elif command == "items":
+            print(items)
+            continue
+        elif command.startswith("save "):
+            save_name = command.removeprefix("save ")
+            saves[save_name] = create_save(computer)
+            print(f"Saved game state as {save_name}")
+            continue
+        elif command.startswith("load "):
+            save_name = command.removeprefix("load ")
+            load_save(saves[save_name], computer)
+            print(f"Loaded game state from {save_name}")
+            continue
+        elif command.startswith("take "):
+            items.add(command.removeprefix("take "))
+        elif command.startswith("drop "):
+            items.remove(command.removeprefix("drop "))
+        elif command.startswith("force "):
+            direction = command.removeprefix("force ")
+            if force(computer, direction, items):
                 return
-        # TODO: add manual save states.
+            continue
 
-        for c in command:
+        send_command(computer, command)
-            computer.send_input(ord(c))
-
-        computer.send_input(10)  # manually send newline