Add 2021-13 in Python

Signed-off-by: AKU <tom@tdpain.net>

challenges/2021/13-transparentOrigami/README.md

@@ -0,0 +1,2 @@
+# [Day 13: Transparent Origami](https://adventofcode.com/2021/day/13)
+

challenges/2021/13-transparentOrigami/benchmark.json

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+{
+  "day": 13,
+  "dir": "challenges/2021/13-transparentOrigami",
+  "implementations": {
+    "Python": {
+      "part.1.avg": 0.002360786199569702,
+      "part.1.max": 0.004988908767700195,
+      "part.1.min": 0.0005254745483398438,
+      "part.2.avg": 0.006699836015701294,
+      "part.2.max": 0.014143228530883789,
+      "part.2.min": 0.001451253890991211
+    }
+  },
+  "numRuns": 1000
+}

challenges/2021/13-transparentOrigami/info.json

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+{
+    "inputFile": "input.txt",
+    "testCases": {
+        "one": [
+            {
+                "input": "6,10\n0,14\n9,10\n0,3\n10,4\n4,11\n6,0\n6,12\n4,1\n0,13\n10,12\n3,4\n3,0\n8,4\n1,10\n2,14\n8,10\n9,0\n\nfold along y=7\nfold along x=5",
+                "expected": "17"
+            }
+        ],
+        "two": []
+    }
+}

challenges/2021/13-transparentOrigami/py/__init__.py

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+import re
+from typing import Dict, Tuple, List
+from aocpy import BaseChallenge
+from dataclasses import dataclass
+
+
+Point = Tuple[int, int]
+Sheet = Dict[Point, bool]
+
+
+INSTRUCTION_REGEX = re.compile(r"fold along (x|y)=(\d+)")
+
+
+@dataclass
+class Instruction:
+    axis: str
+    n: int
+
+
+def parse(instr: str) -> Tuple[Sheet, List[Instruction]]:
+    sheetPoints, instructions = instr.strip().split("\n\n")
+    
+    sheet = {}
+    for point in sheetPoints.splitlines():
+        x, y = point.split(",")
+        sheet[(int(x), int(y))] = True
+
+    ins = []
+    for line in instructions.splitlines():
+        m = INSTRUCTION_REGEX.match(line)
+        ins.append(Instruction(
+            m.group(1),
+            int(m.group(2)),
+        )
+        )
+
+
+    return sheet, ins
+
+
+def print_sheet(sheet: Sheet):
+    max_x = max(x for x, y in sheet)
+    max_y = max(y for x, y in sheet)
+    lines = []
+    for y in range(max_y + 1):
+        ll = ""
+        for x in range(max_x + 1):
+            ll += "██" if sheet.get((x, y), False) else "  "
+        lines.append(ll)
+    for x in lines:
+        print(x, flush=True)
+
+
+def apply_instruction(sheet: Sheet, instruction: Instruction) -> Sheet:
+
+    # max_val = max((x for x, _ in sheet) if instruction.axis == "x" else (y for _, y in sheet))
+
+    def mod_point(p: Point) -> Point:
+        v = p[0]
+        if instruction.axis == "y":
+            v = p[1]
+
+        if v > instruction.n:
+            if instruction.axis == "x":
+                return (instruction.n - (p[0] - instruction.n), p[1])
+            elif instruction.axis == "y":
+                return (p[0], instruction.n - (p[1] - instruction.n))
+            raise ValueError(f"unknown axis {instruction.axis}")
+        
+        return p
+
+    new_sheet = {}
+    for point in sheet:
+        new_sheet[mod_point(point)] = True
+
+    return new_sheet
+
+
+class Challenge(BaseChallenge):
+
+    @staticmethod
+    def one(instr: str) -> int:
+        sheet, instructions = parse(instr)
+        sheet = apply_instruction(sheet, instructions[0])
+        return sum(sheet.values())
+
+    @staticmethod
+    def two(instr: str) -> str:
+        sheet, instructions = parse(instr)
+        for instruction in instructions:
+            sheet = apply_instruction(sheet, instruction)
+        print_sheet(sheet)
+        return "work it out yourself"

challenges/2021/README.md

@@ -22,6 +22,7 @@ Solutions to the [2021 Advent of Code](https://adventofcode.com/2021).
 | 10 - Syntax Scoring                 | Complete           | [Python](10-syntaxScoring/py)                                                                           | I can't say I've ever broken something so thoroughly that it has a syntax error on *every* line...                                  |
 | 11 - Dumbo Octopus                  | Complete           | [Python](11-dumboOctopus/py), [Nim](11-dumboOctopus/nim)                                                | Cellular automata my beloved <3                                                                                                     |
 | 12 - Passage Pathing                | Complete           | [Go](12-passagePathing/go)                                                                              | I couldn't tell you how it works, but it does kinda work and I think I have a vague idea (external help was used).                  |
+| 13 - Transparent Origami            | Complete           | [Python](13-transparentOrigami/py)                                                                      | I got stuck for hours on an intermittent off-by-one error. :(                                                                       |
 
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