perf: optimize solution 2025/03

src/solution/year_2025/day_03.py

@@ -1,59 +1,46 @@
 from typing import Any
 
 
-def find_max_subnumber(numbers: list[int], length: int) -> int:
-    numbers = list(reversed(numbers))
-    max_search_index = len(numbers)
-    n = 0
-
+def _find_max_subnumber(numbers: list[int], length: int) -> int:
     if length > len(numbers):
         raise ValueError("length greater than numbers length")
 
-    for start_idx in range(length - 1, -1, -1):
-        # local number and loacal max search index
-        ln, lmsi = 0, 0
-        # search from start_idx up to max_search_index
-        for idx in range(start_idx, max_search_index):
-            m = numbers[idx]
-            if idx >= max_search_index:
-                max_search_index = lmsi
-                break
-            # find leftmost highst number and update found digit and local max index
-            if m >= ln:
-                ln = m
-                lmsi = idx
+    remove = len(numbers) - length
+    stack = []
 
-        max_search_index = lmsi
-        n += ln
-        n *= 10
+    for n in numbers:
+        while remove and stack and stack[-1] < n:
+            stack.pop()
+            remove -= 1
+        stack.append(n)
 
-    return n // 10
+    res = 0
+    for digit in stack[:length]:
+        res = res * 10 + digit
+
+    return res
+
+
+def _parse_input(input_data: str) -> list[list[int]]:
+    return [list(map(int, line)) for line in input_data.splitlines()]
 
 
 def part_1(input_data: str) -> Any:
-    s = 0
-    for line in input_data.splitlines():
-        parsed = list(map(int, line))
-        s += find_max_subnumber(parsed, 2)
-    return s
+    return sum(_find_max_subnumber(p, 2) for p in _parse_input(input_data))
 
 
 def part_2(input_data: str) -> Any:
-    s = 0
-    for line in input_data.splitlines():
-        parsed = list(map(int, line))
-        s += find_max_subnumber(parsed, 12)
-    return s
+    return sum(_find_max_subnumber(p, 12) for p in _parse_input(input_data))
 
 
 def test_find_max_subnumber():
-    assert find_max_subnumber([1, 2, 3, 4, 9], 2) == 49
-    assert find_max_subnumber([1, 2, 3, 4, 5], 2) == 45
-    assert find_max_subnumber([5, 4, 3, 2, 1], 2) == 54
-    assert find_max_subnumber([1, 3, 5, 2, 4], 2) == 54
-    assert find_max_subnumber([8, 1, 8, 2, 7, 3], 3) == 887
-    assert find_max_subnumber([1, 9, 2, 8, 3, 7], 3) == 987
-    assert find_max_subnumber([1, 2, 3, 4, 5], 3) == 345
+    assert _find_max_subnumber([1, 2, 3, 4, 9], 2) == 49
+    assert _find_max_subnumber([1, 2, 3, 4, 5], 2) == 45
+    assert _find_max_subnumber([5, 4, 3, 2, 1], 2) == 54
+    assert _find_max_subnumber([1, 3, 5, 2, 4], 2) == 54
+    assert _find_max_subnumber([8, 1, 8, 2, 7, 3], 3) == 887
+    assert _find_max_subnumber([1, 9, 2, 8, 3, 7], 3) == 987
+    assert _find_max_subnumber([1, 2, 3, 4, 5], 3) == 345
 
 
 def test_part_1(example_data):