/* * 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 . */ #include // for NULL #include // for malloc(), free() #include // for assert() #include "bst.h" int Insert(TreeNode *root, void *element, TreeComparator f, TreeNode **newroot) { int compvalue; if (root == NULL) { // we went past a leaf, so do the insert and // update the parent via newroot. TreeNode *newnode = (TreeNode *) malloc(sizeof(TreeNode)); if (newnode == NULL) return 0; newnode->element = element; newnode->left = newnode->right = NULL; *newroot = newnode; return 1; } // not at root, so traverse downwards compvalue = f(element, root->element); if (compvalue > 0) { return Insert(root->right, element, f, &(root->right)); } else if (compvalue < 0) { return Insert(root->left, element, f, &(root->left)); } else { return -1; } } int Lookup(TreeNode *root, void *findme, TreeComparator f, void **element) { int compvalue; // see if we went past a leaf if (root == NULL) return 0; compvalue = f(findme, root->element); if (compvalue == 0) { // found it! *element = root->element; return 1; } // traverse down if (compvalue > 0) return Lookup(root->right, findme, f, element); return Lookup(root->left, findme, f, element); }