feat: day 3 part 2 done

README.md

@@ -5,10 +5,10 @@
 ## Progress
 
 | Day | Name | Part 1 | Part 2 |
-| :-: | :------------------ | :----: | :----: |
+| :-: | :--- | :----: | :----: |
 |  1  |      |   ⭐   |   ⭐   |
 |  2  |      |   ⭐   |   ⭐   |
-|  3  |                     |   ⭐   |        |
+|  3  |      |   ⭐   |   ⭐   |
 |  4  |      |        |        |
 |  5  |      |        |        |
 |  6  |      |        |        |

requirements.txt

@@ -1 +1,6 @@
+iniconfig==2.3.0
+packaging==26.3
+pluggy==1.6.0
+Pygments==2.21.0
+pytest==9.1.1
 ruff==0.16.4

src/modules/__tests__/test_day_3.py

@@ -4,3 +4,8 @@ from src.modules.day_3 import Engine
 def test_engine_parts():
     engine = Engine(r"src/assets/day_3_test.txt")
     assert engine.sum_part_numbers() == 4361
+
+
+def test_gear_ratio():
+    engine = Engine(r"src/assets/day_3_test.txt")
+    assert engine.get_gear_ratio() == 467835

src/modules/day_3.py

@@ -1,22 +1,48 @@
+from functools import total_ordering
+
+
 def run():
     engine = Engine(r"src/assets/day_3.txt")
     print(f"Part number sum: {engine.sum_part_numbers()}")
+    print(f"Gear ratio: {engine.get_gear_ratio()}")
 
 
 class Engine:
     engine: list[str]
-    neutral_char = "."
+    neutral_char: str = "."
+    gear_char: str = "*"
 
     def __init__(self, path: str):
         self.engine = self.read_engine(path)
 
+    def get_gear_ratio(self) -> int:
+        sum = 0
+        for x in range(self.engine.__len__()):
+            for y in range(self.engine[x].__len__()):
+                gear = self.position_is_gear(x, y)
+
+                if gear[0] == True:
+                    n_1 = self.extract_number_from_position(
+                        gear[1][0][0], gear[1][0][1]
+                    )
+                    n_2 = self.extract_number_from_position(
+                        gear[1][1][0], gear[1][1][1]
+                    )
+                    sum += n_1[0] * n_2[0]
+
+        return sum
+
     def sum_part_numbers(self) -> int:
         sum = 0
         for x in range(self.engine.__len__()):
             y = 0
             while y < self.engine[x].__len__():
-                if self.engine[x][y] != self.neutral_char and not self.position_is_symbol(x,y) and self.position_has_part(x,y):
-                    number_pos = self.extract_number_from_position(x,y)
+                if (
+                    self.engine[x][y] != self.neutral_char
+                    and not self.position_is_symbol(x, y)
+                    and self.position_has_part(x, y)
+                ):
+                    number_pos = self.extract_number_from_position(x, y)
                     sum += number_pos[0]
                     y = number_pos[1] - 1
                 y += 1
@@ -35,6 +61,53 @@ class Engine:
 
         return (int(n), y)
 
+    def position_is_gear(self, x: int, y: int) -> tuple[bool, list[tuple[int, int]]]:
+        if x >= self.engine.__len__() or x < 0 or y >= self.engine.__len__() or y < 0:
+            return (False, [])
+        if self.engine[x][y] != self.gear_char:
+            return (False, [])
+
+        total_numbers = 0
+        position_number: list[tuple[int, int]] = []
+        b = self.position_is_number(x + 1, y)
+        t = self.position_is_number(x - 1, y)
+        r = self.position_is_number(x, y + 1)
+        l = self.position_is_number(x, y - 1)
+        bl = self.position_is_number(x + 1, y - 1)
+        br = self.position_is_number(x + 1, y + 1)
+        tl = self.position_is_number(x - 1, y - 1)
+        tr = self.position_is_number(x - 1, y + 1)
+
+        if r is True:
+            position_number.append((x, y + 1))
+            total_numbers += 1
+        if l is True:
+            position_number.append((x, y - 1))
+            total_numbers += 1
+
+        if tl is True:
+            position_number.append((x - 1, y - 1))
+            total_numbers += 1
+        elif t is True:
+            position_number.append((x - 1, y))
+            total_numbers += 1
+
+        if tr is True and t is not True:
+            position_number.append((x - 1, y + 1))
+            total_numbers += 1
+
+        if bl is True:
+            position_number.append((x + 1, y - 1))
+            total_numbers += 1
+        elif b is True:
+            position_number.append((x + 1, y))
+            total_numbers += 1
+
+        if br is True and b is not True:
+            position_number.append((x + 1, y + 1))
+            total_numbers += 1
+
+        return (total_numbers == 2, position_number)
 
     def position_has_part(self, x: int, y: int) -> bool:
         return (
@@ -58,6 +131,8 @@ class Engine:
             return self.engine[x][y] != self.neutral_char
 
     def position_is_number(self, x: int, y: int) -> bool:
+        if x >= self.engine.__len__() or x < 0 or y >= self.engine.__len__() or y < 0:
+            return False
         try:
             int(self.engine[x][y])
             return True