yukicoder contest 293 参戦記 - Qiita

from itertools import product def f(n): a = [(-1, -1), (0, -1), (1, -1), (-1, 1), (1, 1)] result = set() for i in range(n + 1): for p in product(a, repeat=i): x, y = 0, 0 for xx, yy in p: x += xx y += yy result.add((x, y)) return len(result)