add 2024/day19.1

2024/19/main.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python
+# -*- encoding: utf-8; py-indent-offset: 4 -*-
+
+# Author: Sebastian Mark, Christian Hennevogl
+# CC-BY-SA (https://creativecommons.org/licenses/by-sa/4.0/deed.de)
+
+# pylint: disable=missing-module-docstring,missing-function-docstring,consider-using-f-string
+
+
+def readinput():
+    with open("input", "r", encoding="utf-8") as file:
+        lines = file.readlines()
+        towels = [pattern.strip() for pattern in lines[0].split(",")]
+        designs = list(map(str.strip, lines[2:]))
+    return towels, designs
+
+
+# pylint: disable-next=inconsistent-return-statements
+def check_design(design: str, towels: list, cache=None) -> bool:
+    if cache is None:
+        cache = {}
+
+    if design in cache:  # Check if the result for the current design is already cached.
+        return cache[design]
+
+    if not design:  # Base case: empty design means it was successfully constructed.
+        return True
+
+    for towel in towels:
+        if design.startswith(towel):  # Check if the design starts with the towel.
+            if check_design(design.removeprefix(towel), towels, cache):
+                cache[design] = True
+                return True
+
+    cache[design] = False  # Cache the result as False if no valid combination is found.
+
+
+def main():
+    towels, designs = readinput()
+
+    # part 1
+    sorted_towels = sorted(towels, key=len, reverse=True)
+    count = 0
+    for design in designs:
+        if check_design(design, sorted_towels):
+            count += 1
+    print("\nPossible designs: %d" % count)
+
+
+if __name__ == "__main__":
+    main()