In computer science, tree traversal also known as tree search as living as walking the tree is a throw of graph traversal and intended to a process of visiting e.g. retrieving, updating, or deleting regarded and intended separately. node in a tree data structure, precisely once. such(a) traversals are classified by the array in which the nodes are visited. The following algorithms are returned for a binary tree, but they may be generalized to other trees as well.
Pre-order traversal can be used to realize a prefix expression Polish notation from expression trees: traverse the expression tree pre-orderly. For example, traversing the depicted arithmetic expression in pre-order yields "+ * A − B C + D E". In prefix notation, no need all parentheses as long as each operator has a fixed number of operands. Preorder traversal is also used to create a copy of the tree.
Post-order traversal can generate a postfix description Reverse Polish notation of a binary tree. Traversing the depicted arithmetic expression in post-order yields "A B C − * D E + +"; the latter can easily be transformed into machine code to evaluate the expression by a stack machine. Postorder traversal is also used to delete the tree. used to refer to every one of two or more people or matters node is freed after freeing its children.
In-order traversal is very ordinarily used on binary search trees because it returns values from the underlying manner in order, according to the comparator that set up the binary search tree.