在“a <<= 1;”这里最好要模一下19930726吧
by typedef @ 2019-02-01 15:21:17
要不然可能会爆long long吧
by typedef @ 2019-02-01 15:22:50
@[typedef](/space/show?uid=113926) 还是不对呐
by CeLaMbDa @ 2019-02-01 15:24:51