使用 Java 删除二叉搜索树中的节点

Question

Could you tell me why this code wont delete a node in a BST? Is there any logical error in my code?

    // To delete a node from the BST
public Node deleteNode(Node myRoot, int toDel) {
    if (myRoot == null) return null;
    else if (toDel < myRoot.data) myRoot.left = deleteNode(myRoot.left, toDel);
    else if (toDel > myRoot.data) myRoot.right = deleteNode(myRoot.right, toDel);
    else {
        // Leaf node
        if (myRoot.right == null && myRoot.left == null) {
            myRoot = null;
        } else if (myRoot.left == null) { // No left child
            myRoot = myRoot.right;
        } else if (myRoot.right==null){ // No right child
            myRoot = myRoot.left;
        }
    }
    return myRoot;
}

NOTE:- This code only deletes the nodes with one child or no child. I am currently working on deleting a node with 2 children so please dont solve that for me.

Answer 1

If 0 children, simply delete node ( return null for it).

If there is 1 child, simply replace the node with the child that is not null.

public Node deleteNode(Node myRoot, int toDel) {
    if (myRoot == null) {
      return null;
    } else if (myRoot.data == toDel) {
      if (myRoot.left != null) {
          return myRoot.left;
      } else if (myRoot.right != null) {
          return myRoot.right;
      } else {
          return null;
      }
    }
    ...
   return myRoot;
}