2024 day 18

2024/18/first.py

@@ -0,0 +1,40 @@
+from utils import Point, lines
+from collections import deque, namedtuple
+
+def parse(lines):
+    return [Point(*map(int, line.split(','))) for line in lines]
+
+bounds = Point(71, 71)
+
+Node = namedtuple('Node', ['pos', 'cost'])
+
+def solve(points):
+    seen = set([(0,0)])
+    been = set()
+    fringe = deque([Node(Point(0,0), 0)])
+    while fringe:
+        cur = fringe.popleft()
+        been.add(cur.pos)
+        if cur.pos == bounds - (1, 1):
+            return cur.cost
+        for n in cur.pos.neighbors():
+            if n not in bounds or n in points:
+                continue
+            if n not in seen:
+                seen.add(n)
+                fringe.append(Node(n, cur.cost + 1))
+    return None
+    # def draw(x, y):
+    #     if (x, y) in points:
+    #         return '#'
+    #     if (x, y) in been:
+    #         return 'O'
+    #     if (x, y) in seen:
+    #         return '.'
+    #     return ' '
+    # for y in range(bounds.y):
+    #     print(''.join(draw(x, y) for x in range(bounds.x)))
+
+if __name__ == '__main__':
+    points = parse(lines())
+    print(solve(set(points[:1024])))

2024/18/second.py

@@ -0,0 +1,12 @@
+from utils import Point, lines
+from collections import deque, namedtuple
+from first import parse, solve
+
+if __name__ == '__main__':
+    points = parse(lines())
+    fallen = set(points[:1024])
+    for p in points[1024:]:
+        fallen.add(p)
+        if not solve(fallen):
+            print(f'{p.x},{p.y}')
+            break

2024/18/utils.py

@@ -0,0 +1,26 @@
+from enum import IntEnum, auto
+
+def lines():
+    while True:
+        try:
+            yield input()
+        except:
+            break
+
+class Point:
+    __match_args__ = ['x', 'y']
+
+    def __init__(self, x, y): self.x, self.y = x, y
+    def neighbors(self):
+        for d in ((1, 0), (0, 1), (-1, 0), (0, -1)):
+            yield self + d
+    def __add__(self, other): return Point(self.x + other[0], self.y + other[1])
+    def __mul__(self, sca): return Point(self.x * sca, self.y * sca)
+    def __sub__(self, other): return Point(self.x - other[0], self.y - other[1])
+    def __neg__(self): return Point(-self.x, -self.y)
+    def __eq__(self, other): return self.x == other[0] and self.y == other[1]
+    def __getitem__(self, i): return self.x if i == 0 else self.y
+    def __str__(self): return "({}, {})".format(self.x, self.y)
+    def __repr__(self): return "({} {})".format(self.x, self.y)
+    def __hash__(self): return (self.x, self.y).__hash__()
+    def __contains__(self, other): return other[0] in range(self.x) and other[1] in range(self.y)

README.md

@@ -22,14 +22,14 @@ My solutions for the [Advent of Code](https://adventofcode.com), a challenge sta
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-| Total | 10 | 14 | 4 | 12 | 46 | 44 | 50 | 44 | 28
+| Total | 10 | 14 | 4 | 12 | 46 | 44 | 50 | 44 | 30
 
-Total stars: 252
+Total stars: 254