1 #ifndef _SPLAY_TREE_H_
2 #define _SPLAY_TREE_H_
3 
4 typedef struct tree_node {
5     struct tree_node * left, * right;
6     int key;
7     int size;   /* maintained to be the number of nodes rooted here */
8 
9     void *data;
10 } splay_tree;
11 
12 
13 splay_tree * splaytree_splay (splay_tree *t, int key);
14 splay_tree * splaytree_insert(splay_tree *t, int key, void *data);
15 splay_tree * splaytree_delete(splay_tree *t, int key);
16 splay_tree * splaytree_size(splay_tree *t);
17 
18 #define splaytree_size(x) (((x)==NULL) ? 0 : ((x)->size))
19 /* This macro returns the size of a node.  Unlike "x->size",     */
20 /* it works even if x=NULL.  The test could be avoided by using  */
21 /* a special version of NULL which was a real node with size 0.  */
22 
23 
24 #endif
25