Tree Travels In Order Pre-Order And Post Order

Have you ever stopped to wonder about all these applications, software, and programs you use on your systems and how they came to be? Do you know it’s all part of coding? Let’s get to know about Tree Travels In Order Pre-Order And Post Order.

Yeah, coding. It involves giving the computer a set of instructions in binary forms which can be used to set up programs. It’s mostly used by programmers for their work. We have a different kind of coding and in this article, we will deal with something related to them. If you are a programmer or not, I promise you it will certainly be of great help so sit tight and read on.

Tree Traversals

Tree traversals deal with the process of retrieving, each node in a tree data structure exactly once. The sequence in which the nodes are visited is used to classify these traversals. It is widely known that whatever the human mind can fathom, animation can explain it.  This article will teach you not only about the theory behind such algorithms, but also how to put them into practice using code.

We will deal with 

1. In order traversal
2. Pre order traversal 
3. Traversal of the Level Order Traversal of the Postorder

Let’s define a Tree as a data structure before we go into the tree traversal techniques. This will assist you in comprehending the concepts in a meaningful manner. Tree stores information in a hierarchical manner just as it looks in a diagram

Nodes (data) and connections (edges) in a tree should not create a cycle. We have some technical terms in tree traversals. Some of them are

1. Nodes- A node is a structure that can represent a value or a condition.
2. Roots-prime ancestor is the top node in a tree. 
3. Parent – The polar opposite of a child, a direct ancestor.
4. Leaf – a node but it does not have any child. The number of leaves is referred to as the breadth. A subtree is a type of tree.

A traversal tree contains a node and all of its offspring. 

In-order Tree Traversal

The most common kind of DFS (Depth First Search) tree traversal is in order traversal. We’ll start with the depth of the chosen Node, then move on to the breadth at that level, as DFS proposes.

For an in order,  we’ll start at the root node of the tree and work our way down the left subtree in a curvy fashion. We’ll visit that current node and go to the left node of its right subtree once we’ve reached the left node using the aforementioned steps (if exists). To complete the in order traversal, repeat the steps recursively. The steps will be in the following order (in a recursive function)…

1.  Go to the subtree on the left.
2. Pay a visit to Node.
3. Go to the subtree on the right. 

Important Fact: Traversing a Binary Search Tree in reverse order always results in sorted Nodes.

Pre-Order Traversal

.Another DFS version is Preorder Traversal. A recursive function’s atomic actions are the same as in order traversal but in a different order. The current node is visited first, followed by the left sub-tree. After visiting every node in the left sub-tree, we’ll go on to the right sub-tree and repeat the process. The steps will be in the following order.

1.  Visit the Node. 
2. Move to the subtree on the left
3. Check the subtree on the right.

Post-order Traversal

Postorder Traversal is the same way. In recursion, we traverse the left and right subtrees before returning to the current node. As a result, the steps will be performed in the following order: 

1. Check the subtree on the left.
2. Check the subtree on the right.
3.  Visit the node

We also have level order traversal. This is a different traversal than the one we just went over. To visit/modify each node of the tree, level order traversal uses BFS (Breadth-First Search). As suggested by BFS, the tree’s breadth comes first, followed by its depth. This traversal is slightly more difficult to implement than the previous three which is because we must traverse from left to right at the same level, the sequence in which we add children to the queue is critical.

Numerical Explanation Of Tree Traversal In Order, Pre-Order, And Post Order

The following are the most common tree traversal methods. Using a tree as an example

 (a) In order (Left, Root, Right): 4 2 5 1 3

 (b) Preorder (Root, Left, Right): 1 2 4 5 3

 (c) Postorder (Left, Right, Root): 4 5 2 3

We also have binary kinds of tree traversals in which the node can only have two children. Each node has a signifying value. The value of the nodes on the root is greater than the value of the left subtree node while that of the right subtree is the opposite.

In Conclusion

Tree traversals involve revisiting nodes of the tree structure and updating it as you pay a visit to each of the nodes. The way a binary search tree operates is different than how a normal traversal tree operates. Also, every tree always has subtrees. We also have in order traversals, pre-orders, and Post- ordered traversals, and how the algorithm of each traversal is done is different. I hope this has been of help to you in understanding traversals.

Frequently Asked Questions

Question 1. How many offspring can a node have in binary search tree traversals?

A node can only have two offspring.

Question 2 How many types of tree traversal algorithms do we have?

We have two. We have Depth-first search algorithms and breadth-first search algorithms.

Question 3 What is different in order, pre-order, and post-order tree traversals?

There is not much difference between them. It’s just the steps in the visiting the nodes that are different among them

Question 4 What is traversal?

Traversal is visitation and updating of the nodes in the tree. This is what tree traversals is all about.