洛谷P3862 8月月赛B
https://www.luogu.org/problemnew/show/P3862#sub
P3862 8月月赛B
推公式:f(n)->f(n+1)
奇葩的预处理
https://www.luogu.org/problemnew/solution/P3862
https://www.luogu.org/problemnew/show/P3862#sub
P3862 8月月赛B
推公式:f(n)->f(n+1)
奇葩的预处理
https://www.luogu.org/problemnew/solution/P3862