Stefan Röttger

struct node {                 /* node of binary tree */
   T item;                    /* chained items of type T */
   struct node *left, *right; /* pointer to left and right child */
};

typedef struct node
   node_type,                 /* type of node */
   *node_ptr;                 /* type of pointer to node */

node_ptr root=NULL;           /* global root node */