day 5: god save me

day05.py

@@ -0,0 +1,42 @@
+import fileinput
+from collections import defaultdict, deque
+import re
+from copy import deepcopy
+
+input = fileinput.input()
+stacks: list[deque] = []
+
+for y, line in enumerate(input):
+    line = line.rstrip("\n")
+    if "1" in line:
+        continue
+    if not line:
+        break
+
+    for x in range(0, len(line), 4):
+        if y == 0:
+            stacks.append(deque([line[x + 1]] if line[x + 1] != " " else []))
+        elif line[x + 1] != " ":
+            stacks[x // 4].appendleft(line[x + 1])
+
+stacks2 = deepcopy(stacks)
+
+RE = re.compile(r"move (\d+) from (\d+) to (\d+)")
+for line in input:
+    m = RE.match(line)
+    if not m:
+        continue
+
+    n, f, t = int(m[1]), int(m[2]), int(m[3])
+
+    p2stack = []
+    for _ in range(n):
+        c = stacks[f - 1].pop()
+        stacks[t - 1].append(c)
+
+        c = stacks2[f - 1].pop()
+        p2stack.append(c)
+
+    stacks2[t - 1].extend(reversed(p2stack))
+
+print("".join(s[-1] for s in stacks), "".join(s[-1] for s in stacks2))