AoC day 19

2024/day19/day19.py

@@ -0,0 +1,42 @@
+import sys, os, re
+sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'common'))
+from common import open_file, print_and_verify_answer
+
+def parse_file(data_file):
+    towels = data_file[0].strip().split(", ")
+    patterns = [line.strip() for line in data_file[2:]]
+    return towels, patterns
+
+def count_ways_to_form_pattern(pattern, towels, result=None):
+    if result is None:
+        result = {}
+    if pattern in result:
+        return result[pattern]
+    if pattern == "":
+        return 1
+    count = 0
+    for towel in towels:
+        if pattern.startswith(towel):
+            count += count_ways_to_form_pattern(pattern[len(towel):], towels, result)
+    result[pattern] = count
+    return count
+
+def run_part_one(mode, expected = None):
+    data_file = open_file( mode + ".txt")
+    towels, patterns = parse_file(data_file)
+    patterns_achievable = sum(1 for pattern in patterns if count_ways_to_form_pattern(pattern, towels))
+    print_and_verify_answer(mode, "one", patterns_achievable, expected)
+
+def run_part_two(mode, expected = None):
+    data_file = open_file( mode + ".txt")
+    towels, patterns = parse_file(data_file)
+    ways_to_form_patterns = sum(count_ways_to_form_pattern(pattern, towels) for pattern in patterns)
+    print_and_verify_answer(mode, "two", ways_to_form_patterns, expected)
+
+# ADD EXPECTED OUTPUTS TO TESTS HERE 👇
+run_part_one("test", 6)
+run_part_one("test2", 0)
+run_part_one("prod", 300)
+run_part_two("test", 16)
+run_part_two("prod", 624802218898092)
+# Now run it and watch the magic happen 🪄

2024/day19/test.txt

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+r, wr, b, g, bwu, rb, gb, br
+
+brwrr
+bggr
+gbbr
+rrbgbr
+ubwu
+bwurrg
+brgr
+bbrgwb

2024/day19/test2.txt

@@ -0,0 +1,3 @@
+rgb, bwu
+
+rgbwu

README.md

@@ -15,7 +15,7 @@ Started in 2022, but I'll backfill previous years when I need a festive boost.
 ⬜ = incomplete or not attempted  
 
 ### Stats
-**2024:**  🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧⬜⬜⬜⬜⬜⬜⬜ _(36)_  
+**2024:**  🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧🟧⬜⬜⬜⬜⬜⬜ _(38)_  
 **2023:**  🟨🟨🟨🟨🟧🟨🟨🟧⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜ _(16)_  
 **2022:**  🟨🟨🟨🟨🟨🟨🟨🟨🟨🟨🟨🟧🟨🟨⬛⬜⬜⬛⬜⬛🟨⬜🟨⬜⬛ _(36)_  
 **2021:**  🟨🟨🟨🟨🟨🟨🟨🟨⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜⬜ _(16)_