Day 08

day08/part1.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+
+lines = (x.strip() for x in open("input.txt"))
+
+instructions = tuple(int(char == "R") for char in next(lines))
+next(lines)
+nodes = {line[:3]: (line[7:10], line[12:15]) for line in lines}
+
+node = "AAA"
+cnt = 0
+
+while True:
+    for char in instructions:
+        node = nodes[node][char]
+        cnt += 1
+        if node == "ZZZ":
+            print(cnt)
+            exit(0)