2024/d18/ex1/ex1.py

@@ -1,65 +0,0 @@
-#!/usr/bin/env python
-
-import heapq
-import sys
-from typing import Iterator, NamedTuple
-
-
-class Point(NamedTuple):
-    x: int
-    y: int
-
-    def neighbours(self) -> Iterator["Point"]:
-        for dx, dy in (
-            (-1, 0),
-            (1, 0),
-            (0, -1),
-            (0, 1),
-        ):
-            yield Point(self.x + dx, self.y + dy)
-
-
-DIMS = Point(70, 70)
-
-
-def solve(input: str) -> int:
-    def parse(input: list[str]) -> list[Point]:
-        return [Point(*map(int, line.split(","))) for line in input]
-
-    def djikstra(start: Point, end: Point, blocks: set[Point]) -> int:
-        # Priority queue of (distance, point)
-        queue = [(0, start)]
-        seen: set[Point] = set()
-
-        while len(queue) > 0:
-            cost, p = heapq.heappop(queue)
-            if p == end:
-                return cost
-            # We must have seen p with a smaller distance before
-            if p in seen:
-                continue
-            # First time encountering p, must be the smallest distance to it
-            seen.add(p)
-            # Add all neighbours to be visited
-            for n in p.neighbours():
-                if p in blocks:
-                    continue
-                if not 0 <= p.x <= DIMS.x:
-                    continue
-                if not 0 <= p.y <= DIMS.y:
-                    continue
-                heapq.heappush(queue, (cost + 1, n))
-
-        assert False  # Sanity check
-
-    coords = parse(input.splitlines())
-    return djikstra(Point(0, 0), DIMS, set(coords[:1024]))
-
-
-def main() -> None:
-    input = sys.stdin.read()
-    print(solve(input))
-
-
-if __name__ == "__main__":
-    main()

2024/d18/ex2/ex2.py

@@ -1,77 +0,0 @@
-#!/usr/bin/env python
-
-import heapq
-import sys
-from typing import Iterator, NamedTuple
-
-
-class Point(NamedTuple):
-    x: int
-    y: int
-
-    def neighbours(self) -> Iterator["Point"]:
-        for dx, dy in (
-            (-1, 0),
-            (1, 0),
-            (0, -1),
-            (0, 1),
-        ):
-            yield Point(self.x + dx, self.y + dy)
-
-
-DIMS = Point(70, 70)
-
-
-def solve(input: str) -> str:
-    def parse(input: list[str]) -> list[Point]:
-        return [Point(*map(int, line.split(","))) for line in input]
-
-    def djikstra(start: Point, end: Point, blocks: set[Point]) -> int | None:
-        # Priority queue of (distance, point)
-        queue = [(0, start)]
-        seen: set[Point] = set()
-
-        while len(queue) > 0:
-            cost, p = heapq.heappop(queue)
-            if p == end:
-                return cost
-            # We must have seen p with a smaller distance before
-            if p in seen:
-                continue
-            # First time encountering p, must be the smallest distance to it
-            seen.add(p)
-            # Add all neighbours to be visited
-            for n in p.neighbours():
-                if p in blocks:
-                    continue
-                if not 0 <= p.x <= DIMS.x:
-                    continue
-                if not 0 <= p.y <= DIMS.y:
-                    continue
-                heapq.heappush(queue, (cost + 1, n))
-
-        return None
-
-    def bisect_cutoff(start: Point, end: Point, blocks: list[Point]) -> Point:
-        # Cutting off the path is monotonic: once cut-off, it's never uncut
-        low, high = 0, len(blocks)
-        while low < high:
-            mid = low + (high - low + 1) // 2
-            if djikstra(start, end, set(blocks[:mid])) is None:
-                high = mid - 1
-            else:
-                low = mid
-        return blocks[low]
-
-    coords = parse(input.splitlines())
-    byte = bisect_cutoff(Point(0, 0), DIMS, coords)
-    return f"{byte.x},{byte.y}"
-
-
-def main() -> None:
-    input = sys.stdin.read()
-    print(solve(input))
-
-
-if __name__ == "__main__":
-    main()