Day5 part1 completed

day5/common.py

@@ -0,0 +1,48 @@
+def parse(filename: str) -> tuple[list[tuple[int, int]], list[tuple[int, ...]]]:
+    page_orders = []
+    updates = []
+    with open(filename) as f:
+        first_part = True
+        while line := f.readline():
+            if first_part and line != "\n":
+                page_orders.append(tuple(map(int, line.strip().split("|"))))
+            else:
+                first_part = False
+            if not first_part and line != "\n":
+                updates.append(tuple(map(int, filter(lambda x: x != "", line.strip().split(",")))))
+    return page_orders, list(map(lambda u: tuple(map(int, u)), updates))
+
+
+def get_middle_page(update: tuple[int, ...]) -> int:
+    return update[int(len(update) / 2)]
+
+
+def update_is_correct(
+    update: tuple[int, ...], not_before: dict[int, list[int]], not_after: dict[int, list[int]]
+) -> bool:
+    correct = True
+    for index, page in enumerate(update[:-1]):
+        correct = all(
+            map(
+                lambda x: x in not_before.get(page, []) and x not in not_after.get(page, []),
+                update[index + 1 :],
+            )
+        )
+        if not correct:
+            break
+    return correct
+
+
+def condense_page_orders(page_orders: list[tuple[int, int]]) -> tuple[dict[int, list[int]], dict[int, list[int]]]:
+    not_before = {}
+    not_after = {}
+    for item in page_orders:
+        if item[0] in not_before:
+            not_before[item[0]].append(item[1])
+        else:
+            not_before[item[0]] = [item[1]]
+        if item[1] in not_after:
+            not_after[item[1]].append(item[0])
+        else:
+            not_after[item[1]] = [item[0]]
+    return not_before, not_after

day5/part1.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python
+from common import condense_page_orders, get_middle_page, parse, update_is_correct
+
+
+def solve(input: tuple[list[tuple[int, int]], list[tuple[int, ...]]]) -> int:
+    raw_page_orders, updates = input
+    not_before, not_after = condense_page_orders(raw_page_orders)
+    middle_pages = [0]
+
+    return sum(middle_pages)
+
+
+def main():
+    print(solve(parse("input")))
+
+
+if __name__ == "__main__":
+    main()

day5/part2.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python
+from common import get_middle_page, parse
+
+
+def update_is_correct(
+    update: tuple[int, ...], not_before: dict[int, list[int]], not_after: dict[int, list[int]]
+) -> bool:
+    correct = True
+    for index, page in enumerate(update[:-1]):
+        correct = all(
+            map(
+                lambda x: x in not_before.get(page, []) and x not in not_after.get(page, []),
+                update[index + 1 :],
+            )
+        )
+        if not correct:
+            break
+    return correct
+
+
+def condense_page_orders(page_orders: list[tuple[int, int]]) -> tuple[dict[int, list[int]], dict[int, list[int]]]:
+    not_before = {}
+    not_after = {}
+    for item in page_orders:
+        if item[0] in not_before:
+            not_before[item[0]].append(item[1])
+        else:
+            not_before[item[0]] = [item[1]]
+        if item[1] in not_after:
+            not_after[item[1]].append(item[0])
+        else:
+            not_after[item[1]] = [item[0]]
+    return not_before, not_after
+
+
+def solve(input: tuple[list[tuple[int, int]], list[tuple[int, ...]]]) -> int:
+    raw_page_orders, updates = input
+    not_before, not_after = condense_page_orders(raw_page_orders)
+    middle_pages = map(get_middle_page, filter(lambda u: update_is_correct(u, not_before, not_after), updates))
+
+    return sum(middle_pages)
+
+
+def main():
+    print(solve(parse("input")))
+
+
+if __name__ == "__main__":
+    main()