feat: aoc 2025 day 6 solution + tests

Author: mbrickerd

_2025/solutions/day06.py

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+"""Day 6: Trash Compactor
+
+This module provides the solution for Advent of Code 2025 - Day 6.
+
+It evaluates cephalopod math worksheets presented in a compacted, column-wise
+format where numbers and operators are aligned vertically across multiple rows.
+
+The module contains a Solution class that inherits from SolutionBase for parsing
+and evaluating these rotated math expressions.
+"""
+
+import math
+
+from aoc.models.base import SolutionBase
+
+
+class Solution(SolutionBase):
+    """Evaluate cephalopod math worksheets in compacted column format.
+
+    This solution processes worksheets where numbers and operators are aligned
+    vertically in columns. Part 1 evaluates problems by grouping numbers and
+    operators by column position. Part 2 handles rotated worksheets by parsing
+    columns in reverse order.
+
+    Uses zip transposition to read columns vertically and dynamic expression
+    evaluation to compute results with both addition and multiplication operators.
+    """
+
+    def part1(self, data: list[str]) -> int:
+        """Evaluate compacted worksheet problems reading columns left-to-right.
+
+        Transposes the worksheet rows into columns, where each column represents
+        either a multi-digit number or an operator (+ or *). Evaluates each
+        vertical math problem using the operator in the final column.
+
+        Args:
+            data: List of worksheet rows as strings
+
+        Returns
+        -------
+            int: Sum of all evaluated math problems from the worksheet
+        """
+        cols = list(zip(*[row.strip().split() for row in data]))
+        score = 0
+
+        for group in cols:
+            nums, operator = group[:-1], group[-1]
+            score += eval(operator.join(nums))
+
+        return score
+
+    def part2(self, data: str) -> int:
+        """Evaluate rotated worksheet problems reading columns right-to-left.
+
+        Parses the worksheet by reversing each row first, then transposing to
+        read columns from right to left. Identifies blank columns as problem
+        separators and evaluates expressions where '*' means multiplication
+        and '+' means addition of all numbers in the problem.
+
+        Args:
+            data: Raw worksheet input as a single string
+
+        Returns
+        -------
+            int: Sum of all evaluated rotated math problems
+        """
+        lines = data.rstrip("\n").splitlines()
+
+        max_width = max(len(line) for line in lines)
+        lines = [line.ljust(max_width) for line in lines]
+
+        operators = []
+        problems = []
+        current_problem = []
+
+        for col in zip(*[line[::-1] for line in lines]):
+            if all(char == " " for char in col):
+                continue
+
+            digit_chars = [char for char in col[:-1] if char != " "]
+            has_digits = bool(digit_chars)
+
+            if has_digits:
+                current_problem.append(int("".join(digit_chars)))
+
+            if col[-1] != " ":
+                operators.append(col[-1])
+                problems.append(current_problem)
+                current_problem = []
+
+        return sum([
+            (math.prod(problem) if operator == "*" else sum(problem))
+            for operator, problem in zip(operators, problems)
+        ])

_2025/tests/data/day06/test_01_input.txt

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+123 328  51 64 
+ 45 64  387 23 
+  6 98  215 314
+*   +   *   +  

_2025/tests/data/day06/test_02_input.txt

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+123 328  51 64
+ 45 64  387 23
+  6 98  215 314
+*   +   *   +

_2025/tests/test_06.py

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+"""Day 6: Trash Compactor
+
+This module contains tests for the Day 6 solution, which evaluates cephalopod
+math worksheets laid out in a compacted, column-wise format. The tests verify:
+
+1. Part 1: Evaluating each vertically aligned problem using the given operator
+2. Part 2: Evaluating rotated worksheet problems with column-based parsing
+"""
+from aoc.models.tester import TestSolutionUtility
+
+
+def test_day06_part1() -> None:
+    """Test evaluating compacted worksheet problems as given.
+
+    This test runs the solution for Part 1 of the puzzle against the
+    provided test input and compares the result with the expected output.
+    """
+    TestSolutionUtility.run_test(
+        year=2025,
+        day=6,
+        is_raw=False,
+        part_num=1,
+        expected=4277556,
+    )
+
+
+def test_day06_part2() -> None:
+    """Test evaluating rotated worksheet problems parsed column-wise.
+
+    This test runs the solution for Part 2 of the puzzle against the
+    provided test input and compares the result with the expected output.
+    """
+    TestSolutionUtility.run_test(
+        year=2025,
+        day=6,
+        is_raw=True,
+        part_num=2,
+        expected=3263827,
+    )