1. Advanced Data Structure using C++

LECTURE NOTES OF ADVANCED DATA STRUCTURE (MT-CSE 110)
comparator that set up the binary search tree (hence the name).To see why this
is the case, note that if n is a node in a binary search tree, then everything in n 's
left subtree is less than n, and everything in n 's right subtree is greater than or
equal to n. Thus, if we visit the left subtree in order, using a recursive call, and
then visit n, and then visit the right subtree in order, we have visited the entire
subtree rooted at n in order. We can assume the recursive calls correctly visit
the subtrees in order using the mathematical principle of structural induction.
Traversing in reverse inorder similarly gives the values in decreasing order.
Preorder traversal
Traversing a tree in preorder while inserting the values into a new tree is
common way of making a complete copy of a binary search tree.One can also
use preorder traversals to get a prefix expression (Polish notation) from
expression trees: traverse the expression tree preorderly. To calculate the value
of such an expression: scan from right to left, placing the elements in a stack.
Each time we find an operator, we replace the two top symbols of the stack
with the result of applying the operator to those elements. For instance, the
expression + 2 3 4, which in infix notation is (2 + 3) 4, would be evaluated
like this:
Using prefix traversal to evaluate an expression tree
Expression (remaining) Stack
+ 2 3 4
Prepared By :­
Er. Harvinder Singh
Assist Prof., CSE, H.C.T.M (Kaithal) Page ‐ 197 ‐