Q. What do you understand by the tree traversal? Write down the procedure for traversing a binary tree in preorder and execute it on the following tree.
Ans:
The algorithm walks through tree data structure and performs some calculation at each node in the tree. This procedure of walking through the tree is called a tree traversal.
There are basically two different methods in which to visit systematically all the nodes of a tree-the depth-first traversal and the breadth-first traversal. Certain depth- first traversal methods happen frequently enough that they are given names of their own: preorder traversal, inorder traversal and postorder traversal.
The algorithm for traversing a tree in preorder is written as follows:-
i. Process the root R.
ii. Traverse left sub tree of R in preorder. iii. Traverse right sub tree of R in preorder. The preorder for the given tree is as follows:-
A L1 R1
A B L1l L1R R1
A B D L1R R1
A B D E R1
A B D E C R1L R1R
A B D E C F R1R
A B D E C F G