update: add remove recursiv

BinaryTree.java

@@ -38,6 +38,40 @@ public class BinaryTree {
     }
   }
 
+  public void remove(int value) {
+    rootNode = removeRecursiv(rootNode, value);
+  }
+
+  private Node removeRecursiv(Node root, int value) {
+    if (root == null) {
+      return null;
+    }
+    
+    if (value < root.getContent()) {
+      root.setLeftNode(removeRecursiv(root.getLeftNode(), value));
+    } else if (value > root.getContent()) {
+      root.setRightNode(removeRecursiv(root.getRightNode(), value));
+    } else {
+      if (root.getLeftNode() == null) {
+        return root.getRightNode();
+      }
+      if (root.getRightNode() == null) {
+        return root.getLeftNode();
+      }
+      Node next = findMinimum(root.getRightNode());
+      root.setContent(next.getContent());
+      root.setRightNode(removeRecursiv(root.getRightNode(), next.getContent())); 
+    }
+    return root;
+  }
+
+  private Node findMinimum(Node root) {
+    if (root.getLeftNode() == null) {
+      return root;
+    }
+    return findMinimum(root.getLeftNode());
+  }
+
   public void insert(int content) {
     if (rootNode == null) {
       Node newNode = new Node(content);