From 3b8a0f9990cbd10170fb563490f28a6bd84eea1b Mon Sep 17 00:00:00 2001
From: Tom van der Lee <tom@vanderlee.io>
Date: Tue, 5 Dec 2023 10:06:58 +0100
Subject: Day5 part 1

---
 day5/__init__.py | 128 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 128 insertions(+)
 create mode 100644 day5/__init__.py

(limited to 'day5/__init__.py')

diff --git a/day5/__init__.py b/day5/__init__.py
new file mode 100644
index 0000000..3189a07
--- /dev/null
+++ b/day5/__init__.py
@@ -0,0 +1,128 @@
+# -*- coding: utf-8 -*-
+from abc import ABC
+from dataclasses import dataclass
+from multiprocessing import Pool
+from typing import Iterator
+
+from aoc import BaseAssignment
+
+
+@dataclass
+class InnerMapping:
+    source: int
+    destination: int
+    length: int
+
+    def __getitem__(self, item):
+        if self.source <= item < self.source + self.length:
+            return self.destination + item - self.source
+        raise KeyError()
+
+
+class Mapping:
+    def __init__(self):
+        self.mappings = []
+
+    def __getitem__(self, item):
+        for mapping in self.mappings:
+            try:
+                return mapping[item]
+            except KeyError:
+                continue
+
+        return item
+
+    def update(self, source: int, destination: int, length: int):
+        self.mappings.append(InnerMapping(source, destination, length))
+
+
+I = tuple[list[int], list[Mapping]]
+T = int
+
+
+class Assignment(BaseAssignment, ABC):
+    @staticmethod
+    def map_seed_position(seed: int, mappings: list[Mapping]) -> int:
+        value = seed
+        for item in mappings:
+            value = item[value]
+
+        return value
+
+    def read_input(self, example=False) -> I:
+        seeds, *almanac = super().read_input(example)
+        _, seeds = seeds.split(": ")
+        seeds = [int(i) for i in seeds.split(" ")]
+
+        maps: list[Mapping] = []
+        map = None
+
+        index = 0
+        while True:
+            try:
+                line = almanac[index]
+            except IndexError:
+                break
+
+            if line == "":
+                index += 2
+
+                if map is not None:
+                    maps.append(map)
+                    map = None
+
+                continue
+            else:
+                index += 1
+
+            if map is None:
+                map = Mapping()
+
+            destination, source, length = line.split(" ")
+            map.update(int(source), int(destination), int(length))
+
+        return seeds, [*maps, map]
+
+
+class AssignmentOne(Assignment):
+    example_result = 35
+
+    def run(self, input: I) -> T:
+        seeds, almanac = input
+
+        values = []
+        for seed in seeds:
+            values.append(self.map_seed_position(int(seed), almanac))
+
+        return min(values)
+
+
+def run_per_seed_range(index: int, seeds: list[int], almanac: list[Mapping]):
+    seed, length = int(seeds[index]), int(seeds[index + 1])
+
+    value = None
+    for seed in range(seed, seed + length):
+        location = Assignment.map_seed_position(seed, almanac)
+        if value is None or value > location:
+            value = location
+
+    return value
+
+
+class AssignmentTwo(Assignment):
+    example_result = 46
+
+    def run(self, input: I) -> T:
+        seeds, almanac = input
+
+        value = None
+
+        with Pool(processes=len(seeds) // 2) as pool:
+            for v in pool.imap_unordered(
+                lambda index: run_per_seed_range(index, seeds, almanac),
+                range(0, len(seeds), 2),
+            ):
+                if value is None or value > v:
+                    value = v
+
+        return value
-- 
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