From 255c440a98cb6d714ffec21a971df1c8b63b5d96 Mon Sep 17 00:00:00 2001
From: Sven Heidemann <sven.heidemann@sh-edraft.de>
Date: Fri, 9 Dec 2022 12:14:11 +0100
Subject: [PATCH] day 9

---
 src/day9.py | 118 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 118 insertions(+)
 create mode 100644 src/day9.py

diff --git a/src/day9.py b/src/day9.py
new file mode 100644
index 0000000..888e3d4
--- /dev/null
+++ b/src/day9.py
@@ -0,0 +1,118 @@
+from dataclasses import dataclass
+from typing import Optional
+
+from cpl_core.console import Console
+from cpl_core.utils import String
+from cpl_query.enumerable import Enumerable
+from cpl_query.extension import List
+from cpl_core.pipes import *
+
+from aoc.aoc import get_input
+
+# global vars
+day = 9
+aoc_input = get_input(2022, day)
+aoc_input1 = """R 5
+U 8
+L 8
+D 3
+R 17
+D 10
+L 25
+U 20"""
+
+
+@dataclass
+class Position:
+    x: int = 0
+    y: int = 0
+
+    def __repr__(self):
+        return f'({self.x}, {self.y})'
+
+    @property
+    def as_tuple(self) -> tuple[int, int]:
+        return self.x, self.y
+
+
+def get_new_tail(head: Position, tail: Position) -> Position:
+    diff = Position(head.x - tail.x, head.y - tail.y)
+    bias = Position(0 if diff.x == 0 else int(diff.x / abs(diff.x)), 0 if diff.y == 0 else int(diff.y / abs(diff.y)))
+
+    if abs(diff.x) <= 1 and abs(diff.y) <= 1:
+        return tail
+
+    return Position(tail.x + bias.x, tail.y + bias.y)
+
+
+def part1():
+    head = Position(0, 0)
+    tail = Position(0, 0)
+    start = Position(0, 0)
+
+    steps = {tail.as_tuple}
+
+    for line in aoc_input.splitlines():
+        step, width = line.split()
+        for i in range(0, int(width)):
+            match step:
+                case 'R':
+                    head.x += 1
+
+                case 'L':
+                    head.x -= 1
+
+                case 'U':
+                    head.y += 1
+
+                case 'D':
+                    head.y -= 1
+
+            tail = get_new_tail(head, tail)
+            steps.add(tail.as_tuple)
+
+    Console.write_line(start, head, tail)
+    Console.write_line(len(steps), steps)
+
+
+def part2():
+    head = Position(0, 0)
+    tails = List(int).range(0, 9).select(lambda x: Position(0, 0))
+
+    steps = {tails.last().as_tuple}
+
+    for line in aoc_input.splitlines():
+        step, width = line.split()
+        for i in range(0, int(width)):
+            match step:
+                case 'R':
+                    head.x += 1
+
+                case 'L':
+                    head.x -= 1
+
+                case 'U':
+                    head.y += 1
+
+                case 'D':
+                    head.y -= 1
+
+            last_t = head
+            new_tails = List(Position)
+            for t in tails.to_list():
+                new_t = get_new_tail(last_t, t)
+                new_tails.add(new_t)
+                last_t = new_t
+
+            tails = new_tails
+            steps.add(tails.last().as_tuple)
+
+    Console.write_line(head, tails.last())
+    Console.write_line(len(steps), steps)
+
+
+if __name__ == '__main__':
+    Console.write_line(f'Advent of code day {day}')
+    part1()
+    part2()
+    Console.write_line()