2023.11.01

challenges/2023/11-cosmicExpansion/README.md

@@ -0,0 +1 @@
+# [Day 11: Cosmic Expansion](https://adventofcode.com/2023/day/11)

challenges/2023/11-cosmicExpansion/main.py

@@ -0,0 +1,164 @@
+import sys
+import math
+
+
+Coordinate = tuple[int, int]
+Universe = dict[Coordinate, str]
+
+
+def apply_coord_delta(a: Coordinate, b: Coordinate) -> Coordinate:
+    aa, ab = a
+    ba, bb = b
+    return aa + ba, ab + bb
+
+
+def parse(instr: str) -> Universe:
+    res = {}
+    for y, line in enumerate(instr.splitlines()):
+        for x, char in enumerate(line):
+            res[(x, y)] = char
+    return res
+
+
+def print_coord_grid(universe: Universe):
+    n_x = max(map(lambda x: x[0], universe.keys())) + 1
+    n_y = max(map(lambda x: x[1], universe.keys())) + 1
+
+    for y in range(n_y):
+        for x in range(n_x):
+            _debug(universe[(x, y)], end="")
+        _debug()
+
+
+def get_universe_x_size(universe: Universe):
+    return max(map(lambda x: x[0], universe.keys())) + 1
+
+
+def get_universe_y_size(universe: Universe):
+    return max(map(lambda x: x[1], universe.keys())) + 1
+
+
+def expand_universe(universe: Universe):
+    n_x = get_universe_x_size(universe)
+    n_y = get_universe_y_size(universe)
+
+    expand_rows = []
+    expand_cols = []
+
+    for y in reversed(range(n_y)):
+        all_are_empty = True
+        for x in range(n_x):
+            if universe[(x, y)] != ".":
+                all_are_empty = False
+                break
+
+        if all_are_empty:
+            expand_rows.append(y)
+
+    for x in reversed(range(n_x)):
+        all_are_empty = True
+        for y in range(n_y):
+            if universe[(x, y)] != ".":
+                all_are_empty = False
+                break
+
+        if all_are_empty:
+            expand_cols.append(x)
+
+    for src_col_x in reversed(sorted(expand_cols)):
+        for x in reversed(range(src_col_x + 1, get_universe_x_size(universe) + 1)): # we don't want to touch the starting col but we do want to overflow by one
+            for y in range(n_y):
+                universe[(x, y)] = universe[(x - 1, y)]
+
+    n_x = get_universe_x_size(universe)
+
+    for src_row_y in reversed(sorted(expand_rows)):
+        for y in reversed(range(src_row_y + 1, get_universe_y_size(universe) + 1)): # we don't want to touch the starting col but we do want to overflow by one
+            for x in range(n_x):
+                universe[(x, y)] = universe[(x, y - 1)]
+
+
+# def heuristic(a: Coordinate, b: Coordinate) -> float:
+#     (c, d) = a
+#     (e, f) = b
+#     return math.sqrt((e - c) ** 2 + (f - d) ** 2)
+
+
+# def get_shortest_path_len(universe: Universe, start: Coordinate, end: Coordinate) -> int:
+#     d = {start: 0}
+#     h = {start: 0}
+#     p = {}
+#     f = {}
+
+#     while end not in d:
+#         w = min(filter(lambda x: x[0] not in f, h.items()), key=lambda x: x[1])[0]
+#         f[w] = None
+
+#         for cardinal_dir in ((-1, 0), (1, 0), (0, -1), (0, 1)):
+#             u = apply_coord_delta(w, cardinal_dir)
+#             if u not in universe:
+#                 continue
+
+#             if u not in d or h[w] + 1 < h[u]:
+#                 d[u] = d[w] + 1
+#                 h[u] = heuristic(w, u)
+#                 p[u] = w
+
+#                 if u == end:
+#                     break
+
+#     return d[end]
+
+def get_shortest_path_len(start: Coordinate, end: Coordinate) -> int:
+    (xa, ya) = start
+    (xb, yb) = end
+    return abs(xb - xa) + abs(yb - ya)
+
+
+def one(instr: str):
+    universe = parse(instr)
+    expand_universe(universe)
+
+    galaxies = []
+    for y in range(get_universe_y_size(universe)):
+        for x in range(get_universe_x_size(universe)):
+            if universe[(x, y)] == "#":
+                galaxies.append((x, y))
+
+    galaxy_pairs = {}
+    for g in galaxies:
+        for h in galaxies:
+            if h == g or (g, h) in galaxy_pairs or (h, g) in galaxy_pairs:
+                continue
+            galaxy_pairs[(g, h)] = None
+    galaxy_pairs = list(galaxy_pairs.keys())
+
+    acc = 0
+    n = len(galaxy_pairs)
+    for i, (a, b) in enumerate(galaxy_pairs):
+        _debug(f"{i}/{n} - ", end="")
+        # h = heuristic(a, b)
+        sp = get_shortest_path_len(a, b)
+        _debug(h, sp)
+        acc += sp
+    return acc
+
+
+def two(instr: str):
+    return
+
+
+def _debug(*args, **kwargs):
+    kwargs["file"] = sys.stderr
+    print(*args, **kwargs)
+
+
+if __name__ == "__main__":
+    if len(sys.argv) < 2 or sys.argv[1] not in ["1", "2"]:
+        print("Missing day argument", file=sys.stderr)
+        sys.exit(1)
+    inp = sys.stdin.read().strip()
+    if sys.argv[1] == "1":
+        print(one(inp))
+    else:
+        print(two(inp))

challenges/2023/11-cosmicExpansion/tests.json

@@ -0,0 +1,8 @@
+{
+    "1": [
+        {
+            "is": "374",
+            "input": "...#......\n.......#..\n#.........\n..........\n......#...\n.#........\n.........#\n..........\n.......#..\n#...#.....\n\n"
+        }
+    ]
+}