05: Solve in Python

05/solution.py

@@ -0,0 +1,29 @@
+#!/usr/bin/env python3
+
+import sys
+import re
+from collections import defaultdict
+
+insr = re.compile(r"move (\d+) from (\d+) to (\d+)")
+
+stacksA = defaultdict(bytearray)
+stacksB = defaultdict(bytearray)
+
+for l in sys.stdin:
+    if "[" in l:
+        for i, c in enumerate(l[1::4], 1):
+            if c != ' ':
+                c = ord(c)
+                stacksA[i].append(c)
+                stacksB[i].append(c)
+
+    im = insr.match(l)
+    if im:
+        n, f, t = map(int, im.groups())
+        stacksA[t] = bytearray(reversed(stacksA[f][:n])) + stacksA[t]
+        stacksA[f] = stacksA[f][n:]
+        stacksB[t] = stacksB[f][:n] + stacksB[t]
+        stacksB[f] = stacksB[f][n:]
+
+print(f"""Silver: {"".join(chr(stacksA[i][0]) for i in sorted(stacksA))}
+Gold: {"".join(chr(stacksB[i][0]) for i in sorted(stacksB))}""")