Solve 2025 day 6

puzzles/solutions/2025/d06/p1.py

@@ -0,0 +1,38 @@
+import functools
+import operator
+import re
+import sys
+from collections.abc import Callable
+
+input_example = """123 328  51 64 
+ 45 64  387 23 
+  6 98  215 314
+*   +   *   +  """
+
+Problem = tuple[list[int], Callable[[int, int], int]]
+
+OPERATIONS_MAP = {"+": operator.add, "*": operator.mul}
+
+
+def get_problems(input_text: str) -> list[Problem]:
+    lines = input_text.splitlines()
+    number_lines = lines[:-1]
+    return [
+        (
+            [int(line[m.start() : m.end()]) for line in number_lines],
+            OPERATIONS_MAP[m.group().strip()],
+        )
+        for m in re.finditer(r"[+*]\s*", lines[-1])
+    ]
+
+
+def get_answer(input_text: str):
+    problems = get_problems(input_text)
+    return sum(
+        functools.reduce(operation, numbers) for (numbers, operation) in problems
+    )
+
+
+if __name__ == "__main__":
+    puzzle_input = sys.argv[1] if len(sys.argv) > 1 else input_example
+    print(get_answer(puzzle_input))

puzzles/solutions/2025/d06/p2.py

@@ -0,0 +1,36 @@
+import functools
+import sys
+
+import p1
+
+
+def transpose_numbers(number_lines: list[str]) -> list[list[int]]:
+    columns_count = len(number_lines[0])
+    number_lines = [
+        [line[column] for line in number_lines] for column in range(columns_count)
+    ]
+    transposed_number_lines = [[]]
+    for line in number_lines:
+        try:
+            transposed_number_lines[-1].append(int("".join(line)))
+        except ValueError:
+            # Whitespace column, create a new problem.
+            transposed_number_lines.append([])
+
+    return transposed_number_lines
+
+
+def get_answer(input_text: str):
+    lines = input_text.splitlines()
+    number_lines, operators_line = lines[:-1], lines[-1]
+    number_lines = transpose_numbers(number_lines)
+
+    return sum(
+        functools.reduce(p1.OPERATIONS_MAP[sign], numbers)
+        for (numbers, sign) in zip(number_lines, operators_line.split(), strict=True)
+    )
+
+
+if __name__ == "__main__":
+    puzzle_input = sys.argv[1] if len(sys.argv) > 1 else p1.input_example
+    print(get_answer(puzzle_input))