Preorder vs Inorder vs Postorder

Preorder Traversal

Preorder traversal is defined as a type of tree traversal that follows the Root-Left-Right policy where:...

In-order Traversal

Inorder traversal is defined as a type of tree traversal technique that follows the Left-Root-Right pattern, such that:...

Postorder Traversal

Postorder traversal is defined as a type of tree traversal that follows the Left-Right-Root policy such that for each node:...

Preorder vs Inorder vs Postorder:

Attribute Pre-order In-order Post-order Visit Order Root, Left Subtree, Right Subtree Left Subtree, Root, Right Subtree Left Subtree, Right Subtree, Root Sorted Order (BST) No Yes Yes Expression Tree Prefix (Polish) Notation Infix (Standard) Notation Postfix (Reverse Polish) Notation Evaluation Order Operators come before operands Operators come between operands Operators come after operands Memory Usage No additional memory for tracking traversal, stack space for recursion/iteration No additional memory for tracking traversal, stack space for recursion/iteration No additional memory for tracking traversal, stack space for recursion/iteration Left-Right Symmetry Not symmetric Symmetric Not symmetric Application Constructing expression trees, cloning/copying trees, prefix notation In-order traversal of BST for sorted order, expression evaluation Deleting nodes in binary trees, post-fix notation, expression evaluation Performance Better for copying/cloning trees, prefix notation Suitable for sorting BST elements, expression evaluation Suitable for deleting nodes, post-fix notation, expression evaluation Tree Modification Easy to copy/cloning, preserving original structure Not ideal for modification Difficult for modification, requires reversing...