1#ifndef _SPLAY_TREE_H_ 2#define _SPLAY_TREE_H_ 3 4typedef 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 13splay_tree * splaytree_splay (splay_tree *t, int key); 14splay_tree * splaytree_insert(splay_tree *t, int key, void *data); 15splay_tree * splaytree_delete(splay_tree *t, int key); 16splay_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