2022-12

Author: viliampucik

2022/12.py

@@ -0,0 +1,39 @@
+#!/usr/bin/env python
+import networkx as nx
+
+
+def path(graph, source, target):
+    try:
+        return nx.shortest_path_length(graph, source, target)
+    except:
+        return -1
+
+
+# fmt: off
+t = {
+    complex(r, c): ord(s)
+    for r, line in enumerate(open(0))
+    for c, s in enumerate(line.strip())
+}
+# fmt: on
+s = next(k for k, v in t.items() if v == ord("S"))
+e = next(k for k, v in t.items() if v == ord("E"))
+
+t[s] = ord("a")
+t[e] = ord("z")
+
+G = nx.DiGraph()
+
+for k, v in t.items():
+    for d in (-1, 1, -1j, 1j):
+        if (n := k + d) in t:
+            if t[n] - v <= 1:
+                G.add_edge(k, n)
+
+print(nx.shortest_path_length(G, s, e))
+# fmt: off
+print(min(
+    l
+    for k, v in t.items()
+    if v == ord("a") and (l := path(G, k, e)) >= 0
+))