135 lines
3.9 KiB
C
135 lines
3.9 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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{
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if (isDuplicate)
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*isDuplicate = 0;
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// Wenn kein Knoten angelegt
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if (root == NULL)
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{
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// Neuen Knoten erstellen
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TreeNode *newNode = malloc(sizeof(TreeNode));
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if (!newNode)
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return NULL;
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// mit Daten füllen
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newNode->data = malloc(dataSize);
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if (!(newNode->data))
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{
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free(newNode);
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return NULL;
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}
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memcpy(newNode->data, data, dataSize);
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newNode->left = NULL; // Kinder NULL setzen
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newNode->right = NULL;
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return newNode;
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}
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// auf Doppellungen überprüfen, daten/werte vergelichen
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// int cmp = compareFct(data, root->data);
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int cmp = compareFct(data, root->data);
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if (cmp == 0) // Duplikat erkannt
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{
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if (isDuplicate) // nicht einfügen
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{
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*isDuplicate = 1;
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return root;
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}
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else // einfügen erlaubt
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{
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root->right = addToTree(root->right, data, dataSize, compareFct, NULL);
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return root;
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}
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}
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// kein Duplikat
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if (cmp < 0)
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{
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root->left = addToTree(root->left, data, dataSize, compareFct, isDuplicate);
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}
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else if (cmp > 0)
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{
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root->right = addToTree(root->right, data, dataSize, compareFct, isDuplicate);
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}
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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; // Stack für Iterator
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static TreeNode *lastRoot = NULL;
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TreeNode *currentNode;
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if (root != NULL) // Initialisierung bei erstem Aufruf
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{
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lastRoot = root;
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if (stack)
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{
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clearStack(stack);
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stack = NULL;
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}
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//leeren Stack initialisieren
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stack = NULL;
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// alle linken Knoten vom Wurzelknoten pushen
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currentNode = root;
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while (currentNode)
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{
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stack = push(stack, currentNode);
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currentNode = currentNode->left;
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}
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}
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// Stack ist leer, keine Daten mehr
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if (!stack)
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return NULL;
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TreeNode *newNode = (TreeNode *)top(stack);
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// Stack-Knoten entfernen
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stack = pop(stack);
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// Wenn rechter Teilbaum vorhanden → alle linken Knoten pushen
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currentNode = newNode->right;
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while (currentNode)
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{
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stack = push(stack, currentNode);
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currentNode = currentNode->left;
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}
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return newNode->data; // Daten zurückgeben
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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)
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{
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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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}
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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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unsigned int size = 0;
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if (root == NULL)
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return 0;
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size = 1 + treeSize(root->left) + treeSize(root->right);
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return size;
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} |