day9 - p2 partial

day09.py

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+from __future__ import annotations
+from tools.aoc import AOCDay
+from typing import Any
+
+
+class Block:
+    file_id: int
+    file_length: int
+    left: Block | None
+    right: Block | None
+
+    def __init__(self, file_id: int, file_length: int, left: Block | None = None):
+        self.file_id = file_id
+        self.file_length = file_length
+        self.left = left
+        self.right = None
+
+
+def get_checksum(head: Block) -> int:
+    checksum = 0
+    index = head
+    count = 0
+    while index is not None:
+        print((str(index.file_id) + "|") * index.file_length, end="")
+        if index.file_id > 0:
+            for _ in range(index.file_length):
+                checksum += index.file_id * count
+                count += 1
+        else:
+            count += index.file_length
+        index = index.right
+
+    print()
+    return checksum
+
+
+class Day(AOCDay):
+    inputs = [
+        [
+            (1928, "input9_test"),
+            (6346871685398, "input9"),
+        ],
+        [
+            (2858, "input9_test"),
+            (None, "input9"),
+        ],
+    ]
+
+    def parse_input(self) -> tuple[Block, Block]:
+        head = Block(-1, 0)
+        tail = head
+        mode = False  # False == file, True == free space
+        file_id = 0
+        for num in map(int, self.getInput()):
+            tail.right = Block(-1 if mode else file_id, num, tail)
+            tail = tail.right
+
+            if mode:
+                file_id += 1
+            mode = not mode
+
+        head = head.right
+        head.left = None
+        return head, tail
+
+    def part1(self) -> Any:
+        head, tail = self.parse_input()
+
+        index = head
+        while index is not None:
+            if index.file_id != -1:
+                index = index.right
+                continue
+
+            if tail.file_id == -1:
+                tail = tail.left
+                tail.right = None
+
+            if tail.file_length > index.file_length:
+                index.file_id = tail.file_id
+                tail.file_length -= index.file_length
+            elif tail.file_length < index.file_length:
+                space_left = index.file_length - tail.file_length
+                index.file_id = tail.file_id
+                index.file_length = tail.file_length
+                tail = tail.left
+                tail.right = None
+                new_space = Block(-1, space_left, index)
+                new_space.right = index.right
+                index.right = new_space
+            else:
+                index.file_id = tail.file_id
+                tail = tail.left
+                tail.right = None
+
+            index = index.right
+
+        return get_checksum(head)
+
+    def part2(self) -> Any:
+        head, tail = self.parse_input()
+
+        index = tail
+        while index is not None:
+            search = head
+            while search != index:
+                if search.file_id == -1 and search.file_length >= index.file_length:
+                    new_free_space = Block(-1, index.file_length, index.left)
+                    new_free_space.right = index.right
+                    index.left.right = new_free_space
+                    if index.right is not None:
+                        index.right.left = new_free_space
+
+                    search.file_id = index.file_id
+                    if search.file_length > index.file_length:
+                        space_left = search.file_length - index.file_length
+                        search.file_length = index.file_length
+                        new_space = Block(-1, space_left, search)
+                        new_space.right = search.right
+                        search.right.left = new_space
+                        search.right = new_space
+
+                    index = new_free_space
+                    break
+                search = search.right
+
+            index = index.left
+
+        while tail.file_id == -1:
+            tail = tail.left
+            tail.right = None
+
+        return get_checksum(head)
+
+
+if __name__ == "__main__":
+    day = Day(2024, 9)
+    day.run(verbose=True)

inputs/input9_test

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+2333133121414131402