https://yukicoder.me/problems/no/803Once we realize this problem is related to a system of linear equations, this problem has been almost solved. All we have to do is to find the number of solutions of the given linear system.Let u be a so…

https://yukicoder.me/problems/no/802Let us find the number of \(x_1, \ldots, x_N\) such that \(x_1 + \cdots + x_N \le M\) and \( x_1 \ge 0\), \(0 \le x_i \le D_2-D_1 \) for \(2\le i \le N\). The generating function can be written as\begin{…