Special test mathematics 3
A. Solving equation
It is easy to do without considering the two restrictions. Use the board inserting method to divide \ (m \) balls into \ (n \) piles
It's \ (\ binom{m-1}{n-1} \)
The second limit is greater than or equal to, so you can allocate \ (a_i-1 \) to these numbers first
The first restriction is not easy to do directly, so consider i ...
Added by froggie81 on Fri, 07 Jan 2022 13:28:39 +0200