7 files changed, 72 insertions, 4 deletions

diff --git a/aoc/__init__.py b/aoc/__init__.py
index 0257b69..f490bf8 100644
--- a/aoc/__init__.py
+++ b/aoc/__init__.py
@@ -17,7 +17,8 @@ class BaseAssignment(Generic[T, I], ABC):
     def __str__(self):
         return f"{self.__module__}.{self.__class__.__name__}"
 
-    def parse_item(self, item: str) -> Iterator[I]:
+    @classmethod
+    def parse_item(cls, item: str) -> Iterator[I]:
         yield item
 
     @property
diff --git a/aoc/__main__.py b/aoc/__main__.py
index 596abee..96a9b7f 100644
--- a/aoc/__main__.py
+++ b/aoc/__main__.py
@@ -38,7 +38,7 @@ def run(
 
     Assignment = getattr(assignment_day, f"Assignment{AssignmentPart(part).name}")
     assignment = Assignment(
-        path=os.path.dirname(assignment_day.__file__), **dict(kwargs)
+        path=os.path.dirname(assignment_day.__file__), **dict(kwargs or {})
     )
 
     start = perf_counter()
diff --git a/day1/__init__.py b/day1/__init__.py
index ec1c2f2..03d00ff 100644
--- a/day1/__init__.py
+++ b/day1/__init__.py
@@ -6,7 +6,8 @@ from aoc import BaseAssignment, I
 
 
 class Assignment(BaseAssignment, ABC):
-    def parse_item(self, item: str) -> Iterator[I]:
+    @classmethod
+    def parse_item(cls, item: str) -> Iterator[I]:
         [rotation, *places] = item
         places = int("".join(places))
 
diff --git a/day2/__init__.py b/day2/__init__.py
index 882bcad..20e573e 100644
--- a/day2/__init__.py
+++ b/day2/__init__.py
@@ -7,7 +7,8 @@ from aoc import BaseAssignment, I, T
 
 
 class Assignment(BaseAssignment, ABC):
-    def parse_item(self, item: str) -> Iterator[range]:
+    @classmethod
+    def parse_item(cls, item: str) -> Iterator[range]:
         for r in item.split(","):
             [start, end] = r.split("-")
             yield range(int(start), int(end) + 1)
diff --git a/day3/__init__.py b/day3/__init__.py
new file mode 100644
index 0000000..9025f4a
--- /dev/null
+++ b/day3/__init__.py
@@ -0,0 +1,39 @@
+# -*- coding: utf-8 -*-
+from abc import ABC
+from typing import Iterator
+
+from aoc import BaseAssignment
+
+
+class Assignment(BaseAssignment, ABC):
+    @classmethod
+    def parse_item(cls, item: str) -> Iterator[list[int]]:
+        yield [int(i) for i in item]
+
+    @classmethod
+    def find_highest_joltage(cls, item: list[int], n: int) -> int:
+        values = list()
+        item_length = len(item)
+
+        last_index = -1
+        for end_index in range(item_length - n + 1, item_length + 1):
+            start_index = last_index + 1
+            value = max(item[start_index:end_index])
+            last_index = item.index(value, start_index, end_index)
+            values.append(str(value))
+
+        return int("".join(values))
+
+
+class AssignmentOne(Assignment):
+    example_result = 357
+
+    def run(self, input: Iterator[list[int]]) -> int:
+        return sum([self.find_highest_joltage(item, 2) for item in input])
+
+
+class AssignmentTwo(Assignment):
+    example_result = 3121910778619
+
+    def run(self, input: Iterator[list[int]]) -> int:
+        return sum([self.find_highest_joltage(item, 12) for item in input])
diff --git a/day3/example.txt b/day3/example.txt
new file mode 100644
index 0000000..7255fca
--- /dev/null
+++ b/day3/example.txt
@@ -0,0 +1,4 @@
+987654321111111
+811111111111119
+234234234234278
+818181911112111
diff --git a/day3/test_init.py b/day3/test_init.py
new file mode 100644
index 0000000..ae4033e
--- /dev/null
+++ b/day3/test_init.py
@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+import pytest
+
+from day3 import AssignmentOne, AssignmentTwo, Assignment
+
+
+class TestAssignment:
+    data = [
+        ["987654321111111", 2, 98],
+        ["811111111111119", 2, 89],
+        ["234234234234278", 2, 78],
+        ["818181911112111", 2, 92],
+        ["987654321111111", 12, 987654321111],
+        ["811111111111119", 12, 811111111119],
+        ["234234234234278", 12, 434234234278],
+        ["818181911112111", 12, 888911112111],
+    ]
+
+    @pytest.mark.parametrize("battery,n,joltage", data)
+    def test_find_highest_joltage(self, battery: str, n: int, joltage: int):
+        banks = next(Assignment.parse_item(battery))
+        assert Assignment.find_highest_joltage(banks, n) == joltage