103 lines
2.9 KiB
C
103 lines
2.9 KiB
C
#include <string.h>
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#include "stack.h"
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#include "bintree.h"
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//TODO: binären Suchbaum implementieren
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/* * `addToTree`: fügt ein neues Element in den Baum ein (rekursiv),
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* `clearTree`: gibt den gesamten Baum frei (rekursiv),
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* `treeSize`: zählt die Knoten im Baum (rekursiv),
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* `nextTreeData`: Traversierung mit Hilfe des zuvor implementierten Stacks. */
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// Adds a copy of data's pointer destination to the tree using compareFct for ordering. Accepts duplicates
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// if isDuplicate is NULL, otherwise ignores duplicates and sets isDuplicate to 1 (or to 0 if a new entry is added).
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TreeNode *addToTree(TreeNode *root,const void *data,size_t dataSize,CompareFctType compareFct,int *isDuplicate) {
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if (!root) {
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// allocate new node
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TreeNode *node = malloc(sizeof(TreeNode));
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if (!node) return NULL;
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node->data = malloc(dataSize);
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if (!node->data) {
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free(node);
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return NULL;
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}
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memcpy(node->data, data, dataSize);
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node->left = node->right = NULL;
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if (isDuplicate) *isDuplicate = 0;
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return node;
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}
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int cmp = compareFct(data, root->data);
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if (cmp == 0) {
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// duplicate
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if (isDuplicate) *isDuplicate = 1;
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return root; // do not insert duplicate
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}
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if (cmp < 0)
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root->left = addToTree(root->left, data, dataSize, compareFct, isDuplicate);
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else
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root->right = addToTree(root->right, data, dataSize, compareFct, isDuplicate);
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return root;
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}
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// Iterates over the tree given by root. Follows the usage of strtok. If tree is NULL, the next entry of the last tree given is returned in ordering direction.
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// Use your implementation of a stack to organize the iterator. Push the root node and all left nodes first. On returning the next element,
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// push the top node and push all its left nodes.
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void *nextTreeData(TreeNode *root)
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{
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static StackNode *stack = NULL;
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// New tree → reset stack and push left path
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if (root != NULL) {
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clearStack(stack);
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stack = NULL;
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TreeNode *curr = root;
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while (curr) {
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stack = push(stack, curr);
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curr = curr->left;
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}
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}
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// No tree / finished
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if (!stack) return NULL;
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// Top node
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TreeNode *node = top(stack);
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stack = pop(stack);
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// After returning node, push its right subtree (all left nodes)
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TreeNode *curr = node->right;
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while (curr) {
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stack = push(stack, curr);
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curr = curr->left;
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}
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return node->data;
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}
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// Releases all memory resources (including data copies).
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void clearTree(TreeNode *root)
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{
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if (!root) return;
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clearTree(root->left);
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clearTree(root->right);
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free(root->data);
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free(root);
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}
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// Returns the number of entries in the tree given by root.
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unsigned int treeSize(const TreeNode *root)
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{
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if (!root) return 0;
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return 1 + treeSize(root->left) + treeSize(root->right);
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} |