3 files changed, 1126 insertions, 0 deletions

diff --git a/day13/__init__.py b/day13/__init__.py
new file mode 100644
index 0000000..41b81dc
--- /dev/null
+++ b/day13/__init__.py
@@ -0,0 +1,109 @@
+import re
+from abc import ABC
+from copy import copy
+from dataclasses import dataclass
+from typing import List, Tuple, Union, TypedDict
+
+from aoc import BaseAssignment
+
+Coordinate = Tuple[int, int]
+
+def mirrored_index(index: int, fold: int) -> int:
+    return fold + (fold - index)
+
+@dataclass
+class Sheet:
+    dots: List[Coordinate]
+    width: int = 0
+    height: int = 0
+
+    def __post_init__(self):
+        x_coordinates, y_coordinates = zip(*self.dots)
+
+        self.width = max(x_coordinates) + 1
+        self.height = max(y_coordinates) + 1
+
+
+    def fold_x(self, position: int):
+        for x, y in copy(self.dots):
+            mirrored_x = mirrored_index(x, position)
+            if mirrored_x < position:
+                self.dots.append((mirrored_x, y))
+                self.dots.remove((x, y))
+
+        self.width = self.width // 2
+        self.dots = list(set(self.dots))
+
+    def fold_y(self, position: int):
+        for x, y in copy(self.dots):
+            mirrored_y = mirrored_index(y, position)
+            if mirrored_y < position:
+                self.dots.append((x, mirrored_y))
+                self.dots.remove((x, y))
+
+        self.height = self.height // 2
+        self.dots = list(set(self.dots))
+
+    def __repr__(self):
+        dots = set(self.dots)
+        return '\n'.join([
+            '',
+            *[
+                ''.join([
+                    '█' if (x, y) in dots else ' '
+                    for x in range(self.width)
+                ])
+                for y in range(self.height)
+            ],
+            '',
+        ])
+
+class Instruction(TypedDict):
+    direction: str
+    position: int
+
+coordinate_regex = re.compile('(\d+),(\d+)')
+instruction_regex = re.compile('fold along (?P<direction>[xy])=(?P<position>\d+)')
+
+class Assignment(BaseAssignment, ABC):
+    def parse_item(self, item: str) -> Union[Coordinate,Instruction]:
+        if coordinate := coordinate_regex.match(item):
+            return tuple(int(i) for i in coordinate.groups())
+
+        if instruction := instruction_regex.match(item):
+            return {
+                **instruction.groupdict(),
+                'position': int(instruction.groupdict()['position'])
+            }
+
+    def read_input(self, example = False) -> Tuple[Sheet, List[Instruction]]:
+        input = super().read_input(example)
+
+        coordinates: List[Coordinate] = []
+
+        while True:
+            coordinate = next(input)
+            if coordinate is None:
+                break
+
+            coordinates.append(coordinate)
+
+        sheet = Sheet(dots=coordinates)
+
+        return sheet, list(input)
+
+
+class AssignmentOne(Assignment):
+    example_result = 17
+
+    def run(self, input: Tuple[Sheet, List[Instruction]]) -> int:
+        sheet, instructions = input
+        getattr(sheet, f'fold_{instructions[0]["direction"]}')(instructions[0]["position"])
+        return len(sheet.dots)
+
+class AssignmentTwo(Assignment):
+    def run(self, input: Tuple[Sheet, List[Instruction]]) -> Sheet:
+        sheet, instructions = input
+        for instruction in instructions:
+            getattr(sheet, f'fold_{instruction["direction"]}')(instruction["position"])
+        return sheet
diff --git a/day13/example.txt b/day13/example.txt
new file mode 100644
index 0000000..282114c
--- /dev/null
+++ b/day13/example.txt
@@ -0,0 +1,21 @@
+6,10
+0,14
+9,10
+0,3
+10,4
+4,11
+6,0
+6,12
+4,1
+0,13
+10,12
+3,4
+3,0
+8,4
+1,10
+2,14
+8,10
+9,0
+
+fold along y=7
+fold along x=5
diff --git a/day13/input.txt b/day13/input.txt
new file mode 100644
index 0000000..0c5500b
--- /dev/null
+++ b/day13/input.txt
@@ -0,0 +1,996 @@
+381,143
+954,841
+1061,183
+654,247
+30,192
+72,215
+1223,680
+512,367
+150,747
+85,890
+495,127
+714,710
+31,238
+242,878
+1218,772
+862,654
+1190,710
+112,229
+276,679
+1225,240
+1104,654
+1120,175
+266,690
+142,79
+977,639
+626,203
+1134,147
+898,206
+438,731
+75,800
+731,576
+932,287
+283,236
+659,222
+241,751
+682,182
+305,612
+651,218
+152,491
+890,100
+788,823
+1198,229
+842,189
+1283,789
+887,113
+17,679
+92,122
+831,21
+894,637
+803,52
+1235,36
+373,669
+512,444
+864,376
+184,316
+104,822
+303,340
+82,289
+465,878
+890,794
+1041,29
+925,116
+847,553
+905,330
+296,382
+708,387
+1255,718
+530,669
+977,460
+1153,568
+30,30
+350,740
+872,781
+944,893
+1069,143
+438,427
+1222,425
+925,555
+1034,215
+547,379
+1233,567
+982,373
+1054,754
+110,508
+214,550
+291,505
+1036,163
+1089,834
+1223,214
+569,415
+1179,534
+529,578
+206,654
+1082,551
+495,655
+353,871
+528,838
+224,431
+380,283
+455,505
+1168,130
+626,483
+687,758
+3,672
+55,340
+907,599
+124,369
+328,73
+1123,396
+194,171
+903,892
+80,660
+277,184
+1233,631
+736,821
+13,750
+562,502
+1307,373
+447,65
+654,763
+43,130
+781,578