I made it
The problem was with one pointer referring to NULL value.
Here is the corrected version:
struct pnode *bform(struct pnode *coeff, int a)
struct pnode *p=coeff;
struct pnode *temp1=p;
struct pnode *proba=NULL;
So, if anyone needs this prog for computing Horne's scheme, I ll translate it and upload.
It's not a big deal, but I couldn't find anyone did this using linked lists.
It's way easier with arrays.