wrote first version of addToTree() and wrote new recursive function addToTreeRec()

bintree.c

@@ -2,19 +2,80 @@
 #include "stack.h"
 #include "bintree.h"
 
+
 //TODO: binären Suchbaum implementieren
 /*  * `addToTree`: fügt ein neues Element in den Baum ein (rekursiv),
     * `clearTree`: gibt den gesamten Baum frei (rekursiv),
     * `treeSize`: zählt die Knoten im Baum (rekursiv),
     * `nextTreeData`: Traversierung mit Hilfe des zuvor implementierten Stacks. */
 
+
+    static TreeNode *root = NULL;
+
+
+    TreeNode        *addToTree      (TreeNode *root, const void *data, size_t dataSize, CompareFctType compareFct, int *isDuplicate);
+    void            *nextTreeData   (TreeNode *root);
+    void            clearTree       (TreeNode *root);
+    unsigned int    treeSize        (const TreeNode *root);
+
+    // selfdeclaredfunctions
+    TreeNode        *addToTreeRec   (TreeNode *currentNode, TreeNode *newNode, CompareFctType compareFct, int *isDuplicate);
+
+
 // Adds a copy of data's pointer destination to the tree using compareFct for ordering. Accepts duplicates
 // if isDuplicate is NULL, otherwise ignores duplicates and sets isDuplicate to 1 (or to 0 if a new entry is added).
+
+//      returned Value is new root?
 TreeNode *addToTree(TreeNode *root, const void *data, size_t dataSize, CompareFctType compareFct, int *isDuplicate)
 {
+    // create a node
+    TreeNode *newNode;
 
+
+    newNode         = calloc(1, sizeof(TreeNode));
+    newNode->data   = calloc(1, dataSize);
+    newNode->left   = NULL;
+    newNode->right  = NULL;
+    memcpy(newNode->data, data, dataSize);
+
+
+    return addToTreeRec(root, newNode, compareFct, isDuplicate);
 }
 
+
+TreeNode *addToTreeRec(TreeNode *currentNode, TreeNode *newNode, CompareFctType compareFct, int *isDuplicate)
+{
+    if (currentNode == NULL)
+    {
+        isDuplicate = 0;
+        return newNode;
+    }
+    else if (compareFct(newNode->data, currentNode->data) < 0)
+    {
+        currentNode->left   = addToTreeRec(currentNode->left, newNode, compareFct, isDuplicate);
+    }
+    else if (compareFct(newNode->data, currentNode->data) > 0)
+    {
+        currentNode->right  = addToTreeRec(currentNode->right, newNode, compareFct, isDuplicate);
+    }
+    else
+    {
+        //duplicate
+        if (isDuplicate == NULL)
+        {
+            return newNode;
+        }
+        else
+        {
+            isDuplicate = 1;
+        }
+    }
+
+
+    return currentNode;
+}
+ 
+
 // 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.
 // Use your implementation of a stack to organize the iterator. Push the root node and all left nodes first. On returning the next element,
 // push the top node and push all its left nodes.
@@ -23,14 +84,17 @@ void *nextTreeData(TreeNode *root)
 
 }
 
+
 // Releases all memory resources (including data copies).
 void clearTree(TreeNode *root)
 {
 
 }
 
+
 // Returns the number of entries in the tree given by root.
 unsigned int treeSize(const TreeNode *root)
 {
 
 }
+