From b6751db2cd765d53d36a63d6a5e7c4c1b438e11a Mon Sep 17 00:00:00 2001
From: Tom van der Lee <tom@vanderlee.io>
Date: Wed, 8 Dec 2021 11:27:20 +0100
Subject: Day 8

---
 day8/__init__.py | 112 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 112 insertions(+)
 create mode 100644 day8/__init__.py

(limited to 'day8/__init__.py')

diff --git a/day8/__init__.py b/day8/__init__.py
new file mode 100644
index 0000000..4a72c1f
--- /dev/null
+++ b/day8/__init__.py
@@ -0,0 +1,112 @@
+from collections import Counter
+from copy import copy
+from typing import List, Tuple, Dict, FrozenSet
+
+from aoc import BaseAssignment
+
+class UnknownException(Exception):
+    pass
+
+Item = FrozenSet[str]
+Information = Tuple[List[Item], List[Item]]
+
+class Assignment(BaseAssignment):
+    def parse_item(self, item: str) -> Tuple[List[Item], List[Item]]:
+        input, output = item.split('|')
+
+        return (
+            [frozenset(i.strip()) for i in input.split(' ') if i != ''],
+            [frozenset(i.strip()) for i in output.split(' ') if i != '']
+        )
+
+    def read_input(self, example = False) -> List[Tuple[List[str], List[str]]]:
+        return list(super().read_input(example))
+
+    @staticmethod
+    def calc_digit(item: Item, known_numbers: Dict[int, Item] = None) -> int:
+        if known_numbers is None:
+            known_numbers = {}
+
+        match len(item):
+            case 2:
+                return 1
+            case 3:
+                return 7
+            case 4:
+                return 4
+            case 5:
+                if 1 in known_numbers and item.issuperset(known_numbers[1]):
+                    return 3
+                elif 4 in known_numbers and len(item | known_numbers[4]) == 7:
+                    return 2
+                else:
+                    return 5
+            case 6:
+                if 1 in known_numbers and not item.issuperset(known_numbers[1]):
+                    return 6
+                elif 3 in known_numbers and item.issuperset(known_numbers[3]):
+                    return 9
+                else:
+                    return 0
+            case 7:
+                return 8
+            case _:
+                raise UnknownException()
+
+    @staticmethod
+    def unique_filter(item: Item) -> bool:
+        try:
+            return Assignment.calc_digit(item) in [1, 4, 7, 8]
+        except UnknownException:
+            return False
+
+
+class AssignmentOne(Assignment):
+    example_result = 26
+
+    def run(self, input: List[Information]) -> int:
+        return sum([
+            len(list(filter(Assignment.unique_filter, output)))
+            for _, output in input
+        ])
+
+
+class AssignmentTwo(Assignment):
+    example_result = 61229
+
+    @staticmethod
+    def find_all_numbers(items: List[Item]) -> Dict[int, Item]:
+        known_numbers = {
+            Assignment.calc_digit(item): item
+            for item in filter(Assignment.unique_filter, items)
+        }
+
+        unknown_numbers = {
+            item
+            for item
+            in filter(
+                lambda item: item not in known_numbers.values(),
+                items
+            )
+        }
+
+        while len(unknown_numbers) > 0:
+            for number in copy(unknown_numbers):
+                try:
+                    nr = Assignment.calc_digit(number, known_numbers)
+                    known_numbers[nr] = number
+                    unknown_numbers.remove(number)
+                except UnknownException:
+                    continue
+
+        return known_numbers
+
+    def run(self, input: List[Information]) -> int:
+        return sum([
+            sum(
+                self.calc_digit(item, self.find_all_numbers(input + output))
+                    * (10 ** (len(output) - index - 1))
+                for index, item in enumerate(output)
+            )
+            for input, output in input
+        ])
-- 
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