Solve day 5 part 2

2022/day05_supply_stacks.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import copy
 import dataclasses
 import re
 
@@ -9,14 +10,14 @@ def main(filename: str, expected_part_1: str = None, expected_part_2: str = None
     with open(filename) as f:
         data = f.read().rstrip().split("\n\n")
 
-    data = parse_data(data)
-    solution_part_1 = solve_part_1(data)
+    data_1, data_2 = parse_data(data)
+    solution_part_1 = solve_part_1(data_1)
 
     print(f"1. Found {solution_part_1}")
     if expected_part_1:
         assert expected_part_1 == solution_part_1
 
-    solution_part_2 = solve_part_2(data)
+    solution_part_2 = solve_part_2(data_2)
     print(f"2. Found {solution_part_2}")
     if expected_part_2:
         assert expected_part_2 == solution_part_2
@@ -48,14 +49,15 @@ class Game:
     stacks: list[list[str]]
     instructions: list[Instruction]
 
+    def __str__(self):
+        return "\n".join(map(str, self.stacks))
+
     def play_instructions(self) -> None:
         for instruction in self.instructions:
             self.execute(instruction)
 
     def execute(self, instruction: Instruction) -> None:
-        for _ in range(instruction.quantity):
-            item = self.stacks[instruction.source].pop()
-            self.stacks[instruction.destination].append(item)
+        raise NotImplementedError()
 
     def message(self) -> str:
         msg = ""
@@ -64,14 +66,29 @@ class Game:
                 msg += stack[-1]
         return msg
 
-    def __str__(self):
-        return "\n".join(map(str, self.stacks))
+
+class Game1(Game):
+    def execute(self, instruction: Instruction) -> None:
+        for _ in range(instruction.quantity):
+            item = self.stacks[instruction.source].pop()
+            self.stacks[instruction.destination].append(item)
+
+
+class Game2(Game):
+    def execute(self, instruction: Instruction) -> None:
+        temp_stack = []
+        for _ in range(instruction.quantity):
+            item = self.stacks[instruction.source].pop()
+            temp_stack.append(item)
+        for _ in range(instruction.quantity):
+            item = temp_stack.pop()
+            self.stacks[instruction.destination].append(item)
 
 
 DataType = Game
 
 
-def parse_data(data: list[str]) -> DataType:
+def parse_data(data: list[str]) -> tuple[DataType, DataType]:
     stacks, instructions = data
     parsed_instructions = []
     for instruction in instructions.split("\n"):
@@ -88,7 +105,9 @@ def parse_data(data: list[str]) -> DataType:
                     break
                 stack.append(char)
             parsed_stacks.append(stack)
-    return Game(parsed_stacks, parsed_instructions)
+    return Game1(
+        copy.deepcopy(parsed_stacks), copy.deepcopy(parsed_instructions)
+    ), Game2(copy.deepcopy(parsed_stacks), copy.deepcopy(parsed_instructions))
 
 
 def solve_part_1(data: DataType) -> str:
@@ -97,9 +116,10 @@ def solve_part_1(data: DataType) -> str:
 
 
 def solve_part_2(data: DataType) -> str:
-    return "0"
+    data.play_instructions()
+    return data.message()
 
 
 if __name__ == "__main__":
-    main("inputs/day05-test1", expected_part_1="CMZ")
-    main("inputs/day05")
+    main("inputs/day05-test1", expected_part_1="CMZ", expected_part_2="MCD")
+    main("inputs/day05", expected_part_1="BWNCQRMDB", expected_part_2="NHWZCBNBF")