Solve 2022 day 7 pt 1-2

2022-python/output/day_07.py

@@ -0,0 +1,54 @@
+from collections import defaultdict
+
+from output import ints
+
+
+def solve(data):
+    fs = defaultdict(int)
+    pwd = []
+    for cmd in data.splitlines():
+        if cmd.startswith("$ ls") or cmd.startswith("dir "):
+            continue
+        if cmd.startswith("$ cd"):
+            d = cmd.split()[-1]
+            match d:
+                case "/":
+                    pwd = []
+                case "..":
+                    pwd.pop()
+                case _:
+                    pwd.append(d)
+            continue
+        a = ""
+        w = sum(ints(cmd))
+        # in example input, all directories have distinct names.
+        #
+        # the puzzle input have repeated directory names, e.g. both
+        # /d/a and /c/b/a (a subfolder named "a") exists.
+        #
+        # Furthermore, puzzle input also has cases of /a/b/a,
+        # e.g. a recurring across directory path.
+        #
+        # Lost several hours due to this.
+        fs[a] += w
+        for p in pwd:
+            a += f"/{p}"
+            fs[a] += w
+    p1 = sum(i for i in fs.values() if i <= 100_000)
+    free = 70_000_000 - fs[""]
+    needed = 30_000_000 - free
+    p2 = min(i for i in fs.values() if i >= needed)
+    return p1, p2
+
+
+if __name__ == "__main__":
+    with open("./input/07.txt", "r") as f:
+        inp = f.read().strip()
+
+    p1, p2 = solve(inp)
+
+    print(p1)
+    print(p2)
+
+    assert p1 == 1644735
+    assert p2 == 1300850