Suppose the heap data structure is implemented with the modified binary tree nodes defined below. The parent variable in the dugum data structure is the pointer to the parent of the corresponding node (added to provide access from a node to its parent). The added variable in the heap data structure shows the sign of the node that was added to the data structure last. Accordingly, write the delete_max function for the heap whose definition is given below.

struct dugum {

int key;

struct dugum *parent, *left_link, *right_link;

};

struct heap{

struct dugum *node;

struct dugum *last_insert;