A link which have the equivalent for C code of the functions sum(ismember(A, B, 'rows')) and nchoosek(v,n)

Good evening, I have to make a porting in C code of a m-file (Matlab file) (that is: I have to translate in C code a file written in Matlab). I ask if there exist in C code an equivalent to the following functions in Matlab:

1. the function sum(ismember(A, B, 'rows')) , where A and B are two matrixes of the same number of columns;

2. the function find(ismember(A, B, 'rows') > 0, 1, 'first') , where A and B are two matrixes of the same number of columns;

3. the function nchoosek(v,2), where v is a vector;

4. the function nchoosek(v,3), where v is a vector;

5. the function nchoosek(v,4), where v is a vector;

6. the function nchoosek(v,5), where v is a vector;

7. the function nchoosek(v,6), where v is a vector;

8. the function nchoosek(v,7), where v is a vector;

9. the function nchoosek(v,8), where v is a vector;

10. the function nchoosek(v,9), where v is a vector.

Please, in the case of somebody has already written these functions in C code, have someone any link in internet to suggest me where I can find them? Lorenzo Bussoli