ack/util/grind/avl.h

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1990-08-31 18:22:53 +00:00
/* $Header$ */
/* AVL-trees: trees in which the difference in depth
of the left branch and the right branch is at most one.
Information in the nodes is represented by a pointer, which is to
be supplied by the user. The user is also expected to supply a
comparison routine for each AVL tree. This routine is offered two
parameters, both pointers, and is expected to return:
a negative number if the comparison result is <
0 if the comparison result is =
a positive number if the comparison result is >
*/
typedef struct avl_tree *AVL_tree;
/* extern AVL_tree create_avl_tree(int (*cmp)());
Returns a fresh avl_tree structure. 'cmp' will be used as comparison
routine for this tree.
*/
extern AVL_tree create_avl_tree();
/* extern add_to_avl_tree(AVL_tree tree, char *n);
Adds the information indicated by 'n' to the avl_tree indicated by 'tree'.
*/
extern add_to_avl_tree();
/* extern char *find_ngt(AVL_tree tree, char *n);
Returns the information in the largest node that still compares <= to 'n',
or 0 if not present.
*/
extern char *find_ngt();
/* extern char *find_nlt(AVL_tree tree, char *n);
Returns the information in the largest node that still compares >= to 'n',
or 0 if not present.
*/
extern char *find_nlt();
/* extern char *find_eq(AVL_tree tree, char *n);
Returns the information in the node that compares equal to 'n',
or 0 if not present.
*/
extern char *find_eq();