求质数个数

\(g(n,j)=\sum_{i=1}^n[i\ is\ prime\ or\ minp>p_j]\)
转移减去\(minp=p_j\)
\(g(n,j)=g(n,j-1)-[g(n/p_j,j-1)-g(p_{j-1},j-1)]\)

posted @ 2024-09-20 15:17  _doctorZ  阅读(7)  评论(0编辑  收藏  举报