Day 1

day1.py

@@ -0,0 +1,27 @@
+def part1(digits):
+    return sum(int(d) for i, d in enumerate(digits) if d == digits[(i+1) % len(digits)])
+
+for inp, out in [
+        ('1122', 3),
+        ('1111', 4),
+        ('1234', 0),
+        ('91212129', 9),
+]:
+    assert part1(inp) == out, f'Expected {out}, got {part1(inp)}'
+
+def part2(digits):
+    return sum(int(d) for i, d in enumerate(digits) if d == digits[(i+len(digits)//2) % len(digits)])
+
+for inp, out in [
+        ('1212', 6),
+        ('1221', 0),
+        ('123425', 4),
+        ('123123', 12),
+        ('12131415', 4),
+]:
+    assert part2(inp) == out, f'Expected {out}, got {part2(inp)}'
+
+puzzle_input = 'TODO'
+
+print(part1(puzzle_input))
+print(part2(puzzle_input))