Solve 2023 day 3 part 1

2023/Day3/python/solve.py

@@ -0,0 +1,54 @@
+from pathlib import Path
+import re
+
+def has_adjacent_symbol(matrix, i, start, end):
+    pattern = re.compile("[0-9\.]")
+    # Left
+    if start > 0 and matrix[i][start - 1] != "." and not bool(pattern.match(matrix[i][start - 1])):
+        return True
+    # Right
+    if end < len(matrix[i]) and matrix[i][end] != "." and not bool(pattern.match(matrix[i][end])):
+        return True
+
+    # Above
+    if i > 0:
+        above = matrix[i - 1][max(0, start - 1):min(len(matrix[i]), end + 1)]
+        for sym in above:
+            if not bool(pattern.match(sym)) and sym != ".":
+                return True
+
+    # Below
+    if i < len(matrix) - 1:
+        below = matrix[i + 1][max(0, start - 1):min(len(matrix[i]), end + 1)]
+        for sym in below:
+            if not bool(pattern.match(sym)) and sym != ".":
+                return True
+
+    return False
+
+
+def part1(lines):
+    matrix = [list(line) for line in lines]
+    engine_parts = []
+
+    for i, line in enumerate(matrix):
+        j = 0
+        while j < len(line):
+            if line[j].isdigit():
+                start = j
+                while j < len(line) and line[j].isdigit():
+                    j += 1
+                end = j
+
+                if has_adjacent_symbol(matrix, i, start, end):
+                    number = int("".join(line[start:end]))
+                    engine_parts.append(number)
+            else:
+                j += 1
+
+    return sum(engine_parts)
+
+
+with (Path(__file__).parent / "../input.txt").open() as f:
+    lines = list(map(lambda l: l.strip(), f.readlines()))
+    print(part1(lines))