1 files changed, 31 insertions, 0 deletions
diff --git a/2024/16/python.py b/2024/16/python.py
new file mode 100755
index 0000000..fda3714
--- /dev/null
+++ b/2024/16/python.py
@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+
+from fileinput import input
+
+grid = {
+    complex(idx, idy): c
+    for idy, line in enumerate(input())
+    for idx, c in enumerate(line.strip())
+}
+start = next(p for p, c in grid.items() if c == "S")
+end = next(p for p, c in grid.items() if c == "E")
+
+q = [(0, (start, 1))]
+seen = set()
+while q:
+    curr = min(q, key=lambda x: x[0])
+    d, (pos, vel) = curr
+    q.remove(curr)
+    if (pos, vel) in seen:
+        continue
+    if pos == end:
+        silver = d
+        break
+    seen.add((pos, vel))
+
+    if grid[pos + vel] != "#":
+        q.append((d + 1, (pos + vel, vel)))
+    q.append((d + 1000, (pos, vel * 1j)))
+    q.append((d + 1000, (pos, vel * -1j)))
+
+print("silver:", silver)