From fbe6994e3ac4a439e7a4d08c69de6d82d15a9601 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Anders=20Engl=C3=B6f=20Ytterstr=C3=B6m?= <yttan@fastmail.se>
Date: Tue, 17 Dec 2024 00:17:21 +0100
Subject: [PATCH] Solve 2024:16 pt1 "Reindeer Maze"

---
 2024-python/output/__init__.py |  2 +-
 2024-python/output/day_16.py   | 85 ++++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+), 1 deletion(-)
 create mode 100644 2024-python/output/day_16.py

diff --git a/2024-python/output/__init__.py b/2024-python/output/__init__.py
index 4ad56dc..0f69f41 100644
--- a/2024-python/output/__init__.py
+++ b/2024-python/output/__init__.py
@@ -69,7 +69,7 @@ def mdbg(m):
 def vdbg(seen, h, w):
     """Print-debug visited positions of a matrix"""
     for r in range(h):
-        print("".join(["#" if (r, c) in seen else "." for c in range(w)]))
+        print("".join(["#" if (r, c) in seen else " " for c in range(w)]))
 
 
 def cw(y, x):
diff --git a/2024-python/output/day_16.py b/2024-python/output/day_16.py
new file mode 100644
index 0000000..781c902
--- /dev/null
+++ b/2024-python/output/day_16.py
@@ -0,0 +1,85 @@
+import re
+from collections import Counter, defaultdict, deque
+from heapq import heappop, heappush
+from itertools import chain, combinations, compress, permutations
+
+from output import ADJ, DD, D, ccw, cw, ints, matrix, mdbg, mhd, vdbg
+
+
+def solve(data):
+    grid, H, W = matrix(data)
+    S = [(r, c) for r in range(H) for c in range(W) if grid[r][c] == "S"][0]
+    E = [(r, c) for r in range(H) for c in range(W) if grid[r][c] == "E"][0]
+    p1 = float('inf')
+    Q = deque([(0, (S,), 1)])
+    seen = set()
+    lowest = []
+    while Q:
+        cost, path, facing = heappop(Q)
+        pos = path[-1]
+        if (pos, facing) in seen:
+            continue
+        seen.add((pos, facing))
+        if pos == E:
+            p1 = min(cost, p1)
+            lowest.append(path)
+        r, c = pos
+        for d, delta in enumerate(D):
+            dr, dc = delta
+            if grid[r + dr][c + dc] == "#":
+                continue
+            if abs(facing - d) == 2:
+                continue
+            if d != facing:
+                heappush(Q, (cost + 1000, path, d))
+            else:
+                heappush(Q, (cost + 1, path + ((r + dr, c + dc),), d))
+    return p1, None
+
+
+if __name__ == "__main__":
+    import os
+
+    # use dummy data
+    inp = """
+    #################
+    #...#...#...#..E#
+    #.#.#.#.#.#.#.#.#
+    #.#.#.#...#...#.#
+    #.#.#.#.###.#.#.#
+    #...#.#.#.....#.#
+    #.#.#.#.#.#####.#
+    #.#...#.#.#.....#
+    #.#.#####.#.###.#
+    #.#.#.......#...#
+    #.#.###.#####.###
+    #.#.#...#.....#.#
+    #.#.#.#####.###.#
+    #.#.#.........#.#
+    #.#.#.#########.#
+    #S#.............#
+    #################
+
+
+
+    """.strip()
+
+    # uncomment to instead use stdin
+    # import sys; inp = sys.stdin.read().strip()
+
+    # uncomment to use AoC provided puzzle input
+    with open("./input/16.txt", "r") as f:
+        inp = f.read().strip()
+
+    # uncomment to do initial data processing shared by part 1-2
+    p1, p2 = solve(inp)
+
+    print(p1)
+    os.system(f"echo {p1} | wl-copy")
+    print(p2)
+    os.system(f"echo {p2} | wl-copy")
+
+    # uncomment and replace 0 with actual output to refactor code
+    # and ensure nonbreaking changes
+    # assert p1 == 0
+    # assert p2 == 0