day 3 - part 2

src/aoc_2024/day3/part2.py

@@ -0,0 +1,53 @@
+import re
+from pathlib import Path
+from typing import Match, List, Any
+
+
+def detect_mul(data: str) -> list[Match]:
+    return re.findall(r"mul\((\d{1,3}),(\d{1,3})\)", data)
+
+
+def compute_multiplication(data: str) -> int:
+    result = 0
+    for match in detect_mul(data):
+        left = int(match[0])
+        right = int(match[1])
+        result += left * right
+    return result
+
+
+def find_activated_parts(data: str) -> str:
+    res = []
+
+    start_match = re.search(r"^.*?don't\(\)", data)
+    if start_match:
+        start_data = start_match[0]
+        res.append(start_data)
+        data = data.removeprefix(start_data)
+
+    middle_match = re.search(r"^.*don't\(\)", data)
+    if middle_match:
+        middle_data = middle_match[0]
+        matches = re.findall(r"do\(\).*?don't\(\)", middle_data)
+        res.extend(matches)
+        data = data.removeprefix(middle_data)
+
+    end_match = re.search(r"do\(\).*$", data)
+    if end_match:
+        end_data = end_match[0]
+        res.append(end_data)
+
+    return "".join(res)
+
+
+def main(input_file: Path) -> int:
+    input_data = ""
+    for line in input_file.open():
+        input_data += line.strip()
+    activated_parts = find_activated_parts(input_data)
+    return compute_multiplication(activated_parts)
+
+
+if __name__ == "__main__":
+    file = Path(__file__).parent / "input-data"
+    print(main(file))

tests/aoc_2024/day3/test-data-part2

@@ -0,0 +1 @@
+xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))

tests/aoc_2024/day3/test_part1.py

@@ -61,5 +61,5 @@ def test_compute_multiplication2_from_multiple_muls():
 
 
 def test_main():
-    file = Path(__file__).parent / "test-data"
+    file = Path(__file__).parent / "test-data-part1"
     assert part1.main(file) == 161

tests/aoc_2024/day3/test_part2.py

@@ -0,0 +1,73 @@
+from pathlib import Path
+
+from aoc_2024.day3 import part2
+
+
+def test_find_activated_parts():
+    input_data = "xmul(2,4)&mul[3,7]!^don't()_mdo()ul(5,5)+mudon't()l(32,64](mul(11,8)undo()?mul(8,5))"
+    assert (
+        part2.find_activated_parts(input_data)
+        == "xmul(2,4)&mul[3,7]!^don't()do()ul(5,5)+mudon't()do()?mul(8,5))"
+    )
+
+
+def test_detect_mul_is_successful():
+    res = part2.detect_mul("mul(1,5)")[0]
+    assert res[0] == "1"
+    assert res[1] == "5"
+
+
+def test_detect_mul_with_3_digits_is_successful():
+    assert part2.detect_mul("mul(123,567)")
+
+
+def test_detect_mul_with_4_digits_fails():
+    assert not part2.detect_mul("mul(1234,5678)")
+
+
+def test_detect_mul_with_space_fails():
+    assert not part2.detect_mul("mul(123 ,678)")
+
+
+def test_detect_mul_without_mul_fails():
+    assert not part2.detect_mul("div(1,5)")
+
+
+def test_detect_multiple_muls_is_successful():
+    res = part2.detect_mul(
+        "xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))"
+    )
+    match1 = res[0]
+    assert match1[0] == "2"
+    assert match1[1] == "4"
+    match2 = res[1]
+    assert match2[0] == "5"
+    assert match2[1] == "5"
+    match3 = res[2]
+    assert match3[0] == "11"
+    assert match3[1] == "8"
+    match4 = res[3]
+    assert match4[0] == "8"
+    assert match4[1] == "5"
+
+
+def test_compute_multiplication_from_mul():
+    assert part2.compute_multiplication("mul(1,5)") == 5
+
+
+def test_compute_multiplication2_from_mul():
+    assert part2.compute_multiplication("mul(8,5)") == 40
+
+
+def test_compute_multiplication2_from_multiple_muls():
+    assert (
+        part2.compute_multiplication(
+            "xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))"
+        )
+        == 161
+    )
+
+
+def test_main():
+    file = Path(__file__).parent / "test-data-part2"
+    assert part2.main(file) == 48