[py] Port 2018_10, kinda

py/aoc/__init__.py

@@ -2,7 +2,7 @@ import sys
 import argparse
 from pathlib import Path
 
-from .y2018 import d01, d02, d03, d04, d05, d06, d07, d08, d09
+from .y2018 import d01, d02, d03, d04, d05, d06, d07, d08, d09, d10
 from .y2020 import d10
 from .y2021 import d14
 from .y2022 import d01, d02, d03, d04, d05, d06
@@ -17,6 +17,7 @@ DAYS = {
     "2018_07": y2018.d07.solve,
     "2018_08": y2018.d08.solve,
     "2018_09": y2018.d09.solve,
+    "2018_10": y2018.d10.solve,
     "2020_10": y2020.d10.solve,
     "2021_14": y2021.d14.solve,
     "2022_01": y2022.d01.solve,

py/aoc/y2018/d10.py

@@ -0,0 +1,78 @@
+import re
+
+
+POINT_RE = r"position=<\s*(-?\d+),\s*(-?\d+)> velocity=<\s*(-?\d+),\s*(-?\d+)>"
+
+
+class Point:
+    def __init__(self, pos, vel):
+        self.pos = pos
+        self.vel = vel
+
+    @classmethod
+    def from_line(cls, line):
+        match = re.fullmatch(POINT_RE, line)
+        x, y, dx, dy = map(int, match.groups())
+        return cls((x, y), (dx, dy))
+
+    def step(self):
+        x, y = self.pos
+        dx, dy = self.vel
+        self.pos = (x + dx, y + dy)
+
+
+class Field:
+    def __init__(self, points=None):
+        self.points = points or []
+        self.steps = 0
+
+    @classmethod
+    def from_str(cls, string):
+        points = []
+        for line in string.splitlines():
+            points.append(Point.from_line(line))
+        return cls(points=points)
+
+    def step(self):
+        for point in self.points:
+            point.step()
+        self.steps += 1
+
+    def step_until_in_limits(self):
+        while True:
+            coords = set(point.pos for point in self.points)
+            xs = set(x for (x, _) in coords)
+            ys = set(y for (_, y) in coords)
+
+            if max(xs) - min(xs) < 500:
+                return
+
+            self.step()
+
+            print(min(xs), max(xs), min(ys), max(ys))
+
+    def render(self):
+        coords = set(point.pos for point in self.points)
+        xs = set(x for (x, _) in coords)
+        ys = set(y for (_, y) in coords)
+
+        for y in range(min(ys), max(ys) + 1):
+            for x in range(min(xs), max(xs) + 1):
+                if (x, y) in coords:
+                    print("#", end="")
+                else:
+                    print(".", end="")
+            print()
+
+        print(self.steps)
+
+
+def solve(inputstr):
+    print("Part 1:")
+    field = Field.from_str(inputstr)
+    field.step_until_in_limits()
+    while input() == "":
+        field.render()
+        field.step()
+
+    print("Part 2: NYI")