Since a binary search tree with N nodes has N + 1 null references, half the space allocated in a binary search tree for link information is wasted.
Consider that if a node has a null left child, we make its left child link to its inorder predecessor, and if a node has a null right child, we make its right child link to its inorder successor.
This is known as a threaded tree, and the extra links are called threads.
Question -1 How can we distinguish threads from real children links?
Question -2 Design the routines to perform insertion and deletion into a tree threaded in the manner described above.
Question -3 What is the advantage of using threaded trees?
Please show all your work and give an explanation of steps