n<=3 s=46*n 4<n<=10 s=46*3+86*(n-3) n>=11 s=46*3+86*7+166*(n-10) =if（n<=3,46*n,if（n<=10 ,46*3+86*(n-3) ,46*3+86*7+166*(n-10)）） 相关文章： 2021-11-27 2021-12-12 2021-09-26 2021-08-06 2021-05-13 2022-02-19 2021-09-25