Move Python solutions

Python/2022/09.py

@@ -0,0 +1,37 @@
+from utils.grid import NEIGH_DICT
+
+
+def get_input(puzzle: str) -> list[tuple[int, int, int]]:
+    return [(*NEIGH_DICT[line[0]], int(line[2:])) for line in puzzle.splitlines()]
+
+
+def solve(lines, n):
+    knots: list[tuple[int, int]] = [(0, 0) for _ in range(n)]
+    visited = {knots[-1]}
+    for dx, dy, cnt in lines:
+        for _ in range(cnt):
+            knots[0] = knots[0][0] + dx, knots[0][1] + dy
+            for i in range(1, n):
+                p = knots[i - 1][0] - knots[i][0]
+                q = knots[i - 1][1] - knots[i][1]
+                if abs(p) <= 1 and abs(q) <= 1:
+                    continue
+                knots[i] = knots[i][0] + max(-1, min(p, 1)), knots[i][1] + max(-1, min(q, 1))
+            visited.add(knots[-1])
+    return len(visited)
+
+
+def part1(puzzle: str):
+    lines = get_input(puzzle)
+    return solve(lines, 2)
+
+
+def part2(puzzle: str):
+    lines = get_input(puzzle)
+    return solve(lines, 10)
+
+
+if __name__ == "__main__":
+    from aoc import run
+
+    run(2022, 9, part1, part2)