Implement day 23

2019/aoc2019/day23.py

@@ -0,0 +1,78 @@
+from typing import TextIO
+
+from aoc2019.intcode import read_program, Computer
+
+
+def part1(data: TextIO) -> int:
+    program = read_program(data)
+
+    computers = [Computer(program.copy()) for _ in range(50)]
+
+    for i, computer in enumerate(computers):
+        computer.send_input(i)
+
+    while True:
+        for computer in computers:
+            try:
+                computer.run()
+            except IndexError:
+                computer.send_input(-1)
+
+            while len(computer.output) >= 3:
+                dest = computer.get_output()
+                x = computer.get_output()
+                y = computer.get_output()
+
+                if dest == 255:
+                    return y
+
+                computers[dest].send_input(x)
+                computers[dest].send_input(y)
+
+
+def part2(data: TextIO) -> int:
+    program = read_program(data)
+
+    computers = [Computer(program.copy()) for _ in range(50)]
+
+    for i, computer in enumerate(computers):
+        computer.send_input(i)
+
+    nat_value = None
+    last_sent = None
+
+    while True:
+        is_idle = True
+
+        for computer in computers:
+            try:
+                computer._execute_current()
+                is_idle = False
+            except IndexError:
+                computer.send_input(-1)
+
+            try:
+                computer.run()
+            except IndexError:
+                pass
+
+            while len(computer.output) >= 3:
+                dest = computer.get_output()
+                x = computer.get_output()
+                y = computer.get_output()
+
+                if dest == 255:
+                    nat_value = (x, y)
+                else:
+                    computers[dest].send_input(x)
+                    computers[dest].send_input(y)
+
+        if is_idle:
+            x, y = nat_value
+
+            if last_sent == nat_value:
+                return y
+            else:
+                computers[0].send_input(x)
+                computers[0].send_input(y)
+                last_sent = nat_value

2019/aoc2019/intcode.py

@@ -76,6 +76,9 @@ class Computer:
     def get_output(self) -> int:
         return self.output.popleft()
 
+    def send_input(self, data: int):
+        self.input.append(data)
+
     def _execute_current(self) -> bool:
         """
         Execute a single instruction