深さ優先探索で集合S= [1, 2, 3, 4, 61, 8, 9, 11, 121, 13, 14]の中の最大値を求める。
# https://www.lanqiao.cn/problems/149/learning/?page=1&first_category_id=1&tags=BFS&tag_relation=intersection&difficulty=20 ...