/*
* Copyright 2011 Steven Gribble
*
* This file is the solution to an exercise problem posed during
* one of the UW CSE 333 lectures (333exercises).
*
* 333exercises is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* 333exercises is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with 333exercises. If not, see .
*/
#ifndef _BST_H_
#define _BST_H_
// A "TreeNode" is the structure we use as a node in a BST.
typedef struct TreeNode {
void *element; // the payload of the node
struct TreeNode *left; // the left child, or NULL
struct TreeNode *right; // the right child, or NULL
} TreeNode;
// Customer has to provide us with a comparator function.
typedef int (*TreeComparator)(void *element1, void *element2);
// Push a new element into the tree.
//
// Arguments:
//
// - root: the root of the tree to insert into
// - element: the element to push into the tree
// - f: the comparator function to use to compare nodes
// - newroot: an output parameter with the new root, if appropriate.
//
// Returns:
//
// - 1 if the element was added
// - 0 if we ran out of memory
// - -1 if the element was already in the tree, in which case
// nothing is malloc'ed and the element is not re-added.
// (The element already being in the tree implies the
// comparator returned 0 for some element.)
int Insert(TreeNode *root, void *element,
TreeComparator f, TreeNode **newroot);
// Find an element in the tree.
//
// Arguments:
//
// - root: the root of the tree
// - findme: the element to find
// - f: the comparator function to use to compare nodes
// - element: an output parameter through which the found
// payload is returned
//
// Returns:
//
// - 1 if a matching element was found
// - 0 otherwise
int Lookup(TreeNode *root, void *findme, TreeComparator f,
void **element);
#endif // _BST_H_