就是区间中的满足条件的个数x区间中满足条件的权值和
by Night_Aurora @ 2017-10-24 19:09:14
@[Night\_Aurora](/space/show?uid=25508) 表达式整个看不懂，sigma貌似也不是这么写吧？
by 睿屿青衫 @ 2017-10-24 19:32:47
@[Night\_Aurora](/space/show?uid=25508) 条件又是啥
by 睿屿青衫 @ 2017-10-24 19:36:19
@[睿屿青衫丶](/space/show?uid=49851)
s是区间中w[i]>=W的个数
v是所有满足w[i]>=W的i的v[i]的和
那么这个贡献就是s\*v
by Night_Aurora @ 2017-10-24 19:47:31
@[Night\_Aurora](/space/show?uid=25508) 多谢大佬
by 睿屿青衫 @ 2017-10-24 20:13:11