2022 day 5

adventofcode/2022/day5/day5.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+import fileinput
+import re
+from collections import defaultdict
+
+
+def parse_data(data):
+    stacks, commands = defaultdict(list), []
+    parsing_stacks = True
+    for line in data:
+        if line == "":
+            parsing_stacks = False
+            continue
+        if parsing_stacks:
+            for i, c in enumerate(line):
+                if c.isalpha():
+                    stacks[i].append(c)
+        else:
+            commands.append(tuple(int(x) for x in re.findall(r"\d+", line)))
+
+    stacks = [v[::-1] for k, v in sorted(stacks.items())]
+    return stacks, commands
+
+
+def part1(stacks, commands):
+    for qty, src, dst in commands:
+        for _ in range(qty):
+            x = stacks[src - 1].pop()
+            stacks[dst - 1].append(x)
+    return "".join(s[-1] for s in stacks)
+
+
+def part2(stacks, commands):
+    for qty, src, dst in commands:
+        stacks[dst - 1] += stacks[src - 1][-qty:]
+        stacks[src - 1] = stacks[src - 1][:-qty]
+    return "".join(s[-1] for s in stacks)
+
+
+def main(data):
+    stacks, commands = parse_data(data)
+    print("Part 1: ", part1([s[:] for s in stacks], commands))
+    print("Part 2: ", part2([s[:] for s in stacks], commands))
+
+
+if __name__ == "__main__":
+    with fileinput.input() as f:
+        data = [x.rstrip() for x in f]
+    main(data)