使用C中的链表创建一个稀疏矩阵

I have an assignment which is to create two sparse matrices (A and B) and then adding them up into a third sparse matrix (C). I have already done it with vectors (receiving two sparse vectors and adding them into a third) so I decided it would be easier to use a series of vectors to represent a matrix. In the future, I may need to do it without vectors but with an actual matrix (I even have a psuedo-code of a function that inserts a number into a sparse matrix), so do understand I have an assignment which is to create two spa