Day 04

2023/examples/day04-1.txt

@@ -0,0 +1,6 @@
+Card 1: 41 48 83 86 17 | 83 86  6 31 17  9 48 53
+Card 2: 13 32 20 16 61 | 61 30 68 82 17 32 24 19
+Card 3:  1 21 53 59 44 | 69 82 63 72 16 21 14  1
+Card 4: 41 92 73 84 69 | 59 84 76 51 58  5 54 83
+Card 5: 87 83 26 28 32 | 88 30 70 12 93 22 82 36
+Card 6: 31 18 13 56 72 | 74 77 10 23 35 67 36 11

2023/examples/day04-2.txt

@@ -0,0 +1,6 @@
+Card 1: 41 48 83 86 17 | 83 86  6 31 17  9 48 53
+Card 2: 13 32 20 16 61 | 61 30 68 82 17 32 24 19
+Card 3:  1 21 53 59 44 | 69 82 63 72 16 21 14  1
+Card 4: 41 92 73 84 69 | 59 84 76 51 58  5 54 83
+Card 5: 87 83 26 28 32 | 88 30 70 12 93 22 82 36
+Card 6: 31 18 13 56 72 | 74 77 10 23 35 67 36 11

2023/pyproject.toml

@@ -0,0 +1,16 @@
+[tool.poetry]
+name = "advent of code 2023"
+version = "1.0.0"
+description = "Personal solutions for the Advent of Code 2023"
+authors = ["Gilles Magalhaes <[email protected]>"]
+readme = "README.md"
+
+[tool.poetry.dependencies]
+python = "^3.10"
+
+[tool.poetry.group.dev.dependencies]
+black = "^23.11.0"
+
+[build-system]
+requires = ["poetry-core"]
+build-backend = "poetry.core.masonry.api"

2023/solutions/day01.py

@@ -1,5 +1,6 @@
 import re
 
+
 def solution(input, skip_spelled=False):
     number_mapping = {
         "one": 1,
@@ -10,30 +11,38 @@ def solution(input, skip_spelled=False):
         "six": 6,
         "seven": 7,
         "eight": 8,
-        "nine": 9
+        "nine": 9,
     }
     total = 0
     for line in input.strip().splitlines():
         digit_indices = [(idx, c) for idx, c in enumerate(line) if c.isdigit()]
-        spelled_indices = [
-            (match.start(), str(number_mapping[num])) 
-            for num in number_mapping.keys() 
-            for match in re.finditer(num, line)
-        ] if not skip_spelled else []
+        spelled_indices = (
+            [
+                (match.start(), str(number_mapping[num]))
+                for num in number_mapping.keys()
+                for match in re.finditer(num, line)
+            ]
+            if not skip_spelled
+            else []
+        )
 
         combined = sorted(digit_indices + spelled_indices)
         result = int(combined[0][1] + combined[-1][1])
         total += result
     return total
 
+
 def part_1(input):
     return solution(input, skip_spelled=True)
 
+
 def example_1(input):
     return solution(input, skip_spelled=True)
 
+
 def example_2(input):
     return solution(input)
 
+
 def part_2(input):
     return solution(input)

2023/solutions/day04.py

@@ -0,0 +1,56 @@
+import re
+
+
+def parse_cards(input):
+    cards = {}
+    for line in input.splitlines():
+        card_number = int(line.split(":")[0].split(" ")[-1])
+        winning_numbers, my_numbers = [
+            set([int(n.strip()) for n in re.sub(" +", " ", arr).strip().split(" ")])
+            for arr in line.split(":")[1].split("|")
+        ]
+        cards[card_number] = (winning_numbers, my_numbers)
+    return cards
+
+
+def solution(input):
+    total = 0
+    cards = parse_cards(input)
+    for winning_numbers, my_numbers in cards.values():
+        r = len(my_numbers.intersection(winning_numbers))
+        if r == 0:
+            continue
+        total += 2 ** (r - 1)
+
+    return total
+
+
+def solution_2(input):
+    cards = list(parse_cards(input).items())
+    stack = [v for v in cards]
+    card_count = {}
+    while len(stack) > 0:
+        card_number, (winning_numbers, my_numbers) = stack.pop()
+        wins = len(my_numbers.intersection(winning_numbers))
+        if card_number not in card_count:
+            card_count[card_number] = 0
+        card_count[card_number] += 1
+        stack.extend([cards[card] for card in range(card_number, card_number + wins)])
+
+    return sum(card_count.values())
+
+
+def part_1(input):
+    return solution(input)
+
+
+def part_2(input):
+    return solution_2(input)
+
+
+def example_1(input):
+    return solution(input)
+
+
+def example_2(input):
+    return solution_2(input)

2023/solutions/main.py

@@ -2,6 +2,7 @@
 from pathlib import Path
 import importlib
 
+
 def main():
     days = sorted([p.stem for p in Path(__file__).parent.glob("day*.py")])
 
@@ -13,15 +14,18 @@ def main():
         print(message)
         print("=" * len(message))
         for idx, example in enumerate(examples):
-            result = getattr(module, example)(open(EXAMPLES_DIR / f"{day}-{idx+1}.txt").read())
+            result = getattr(module, example)(
+                open(EXAMPLES_DIR / f"{day}-{idx+1}.txt").read()
+            )
             print(f"  Example {idx+1}:", result)
 
         for idx, part in enumerate(parts):
             result = getattr(module, part)(open(INPUTS_DIR / f"{day}.txt").read())
             print(f"  Part {idx+1}   :", result)
 
-        if didx > 0:
-            print()
+        if didx >= 0:
+            print("\n")
+
 
 if __name__ == "__main__":
     main()