From 12009ebb6a87a06212ea0269d78d101964f0265e Mon Sep 17 00:00:00 2001
From: Daniel Lin <ephemient@gmail.com>
Date: Thu, 5 Dec 2024 05:49:33 -0500
Subject: [PATCH] Day 5: Print Queue

---
 README.md          |  2 +-
 py/aoc2024/day5.py | 94 ++++++++++++++++++++++++++++++++++++++++++++++
 py/pyproject.toml  |  1 +
 3 files changed, 96 insertions(+), 1 deletion(-)
 create mode 100644 py/aoc2024/day5.py

diff --git a/README.md b/README.md
index b978bd1d..effe123f 100644
--- a/README.md
+++ b/README.md
@@ -9,4 +9,4 @@ Development occurs in language-specific directories:
 |[Day2.hs](hs/src/Day2.hs)|[Day2.kt](kt/aoc2024-lib/src/commonMain/kotlin/com/github/ephemient/aoc2024/Day2.kt)|[day2.py](py/aoc2024/day2.py)|[day2.rs](rs/src/day2.rs)|
 |[Day3.hs](hs/src/Day3.hs)|[Day3.kt](kt/aoc2024-lib/src/commonMain/kotlin/com/github/ephemient/aoc2024/Day3.kt)|[day3.py](py/aoc2024/day3.py)|[day3.rs](rs/src/day3.rs)|
 |[Day4.hs](hs/src/Day4.hs)|[Day4.kt](kt/aoc2024-lib/src/commonMain/kotlin/com/github/ephemient/aoc2024/Day4.kt)|[day4.py](py/aoc2024/day4.py)|[day4.rs](rs/src/day4.rs)|
-|[Day5.hs](hs/src/Day5.hs)|[Day5.kt](kt/aoc2024-lib/src/commonMain/kotlin/com/github/ephemient/aoc2024/Day5.kt)|||
+|[Day5.hs](hs/src/Day5.hs)|[Day5.kt](kt/aoc2024-lib/src/commonMain/kotlin/com/github/ephemient/aoc2024/Day5.kt)|[day5.py](py/aoc2024/day5.py)||
diff --git a/py/aoc2024/day5.py b/py/aoc2024/day5.py
new file mode 100644
index 00000000..d204d582
--- /dev/null
+++ b/py/aoc2024/day5.py
@@ -0,0 +1,94 @@
+"""
+Day 5: Print Queue
+"""
+
+from typing import Callable, Iterable, List, Set, Tuple
+
+SAMPLE_INPUT = """
+47|53
+97|13
+97|61
+97|47
+75|29
+61|13
+75|53
+29|13
+97|29
+53|29
+61|53
+97|53
+61|29
+47|13
+75|47
+97|75
+47|61
+75|61
+47|29
+75|13
+53|13
+
+75,47,61,53,29
+97,61,53,29,13
+75,29,13
+75,97,47,61,53
+61,13,29
+97,13,75,29,47
+"""
+
+
+def _parse(data: str) -> Tuple[Set[Tuple[int, int]], List[List[int]]]:
+    (deps, updates) = data.split("\n\n")
+    deps = {
+        tuple(int(page) for page in line.split("|"))
+        for line in deps.splitlines()
+        if line
+    }
+    updates = [
+        [int(page) for page in line.split(",")] for line in updates.splitlines() if line
+    ]
+    return deps, updates
+
+
+def part1(data: str) -> int:
+    """
+    >>> part1(SAMPLE_INPUT)
+    143
+    """
+    deps, updates = _parse(data)
+    return sum(
+        pages[len(pages) // 2]
+        for pages in updates
+        if all((y, x) not in deps for i, x in enumerate(pages) for y in pages[i + 1 :])
+    )
+
+
+def part2(data: str) -> int:
+    """
+    >>> part2(SAMPLE_INPUT)
+    123
+    """
+    deps, updates = _parse(data)
+    return sum(
+        sorted_pages[len(pages) // 2]
+        for pages in updates
+        if pages
+        != (sorted_pages := _partial_sorted(pages, lambda x, y: (y, x) not in deps))
+    )
+
+
+def _partial_sorted[T](iterable: Iterable[T], ok: Callable[[T, T], bool]) -> List[T]:
+    output = list(iterable)
+    i = 0
+    while i < len(output):
+        x = output[i]
+        for j in range(i + 1, len(output)):
+            y = output[j]
+            if not ok(x, y):
+                output[i], output[j] = y, x
+                break
+        else:
+            i += 1
+    return output
+
+
+parts = (part1, part2)
diff --git a/py/pyproject.toml b/py/pyproject.toml
index c2177801..c4e8a04e 100644
--- a/py/pyproject.toml
+++ b/py/pyproject.toml
@@ -28,6 +28,7 @@ day1 = "aoc2024.day1:parts"
 day2 = "aoc2024.day2:parts"
 day3 = "aoc2024.day3:parts"
 day4 = "aoc2024.day4:parts"
+day5 = "aoc2024.day5:parts"
 
 [build-system]
 requires = ["poetry-core"]