@[喵の耳](/space/show?uid=141993) 用线性筛法啊，比这个跑得快多了
by Celestial_Scarlet @ 2019-02-13 14:48:07
@[baoyu](/space/show?uid=93465) 了解了^-^
by 喵の耳 @ 2019-02-13 14:54:14
为什么要用前缀和？
by 喵の耳 @ 2019-02-13 14:56:13
用线筛呀
by AcceptedAccepted @ 2019-03-01 19:55:43