# Short-Questions

Fast solutions for complex problems

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## What is the non recursive algorithm for Postorder traversal of a binary tree?

1) Create an empty stack S. 2) Initialize current node as root 3) Push the current node to S and set current = current->left until current is NULL 4) If current is NULL and stack is not empty then a) Pop the top item from stack. b) Print the popped item, set current = popped_item->right c) Go to step 3.

## What is recursive and non recursive tree traversal?

1. Recursive functions are simpler to implement since you only have to care about a node, they use the stack to store the state for each call. Non-recursive functions have a lot less stack usage but require you to store a list of all nodes for each level and can be far more complex than recursive functions.

What is Postorder traversal for the given tree?

Algorithm Postorder(tree) 1. Traverse the left subtree, i.e., call Postorder(left-subtree) 2. Traverse the right subtree, i.e., call Postorder(right-subtree) 3. Postorder traversal is used to delete the tree.

What is the recursive traversing of post order traversal?

Traversing a tree involves iterating over all nodes in some manner. As the tree is not a linear data structure, there can be more than one possible next node from a given node, so some nodes must be deferred, i.e., stored in some way for later visiting.

### How do you implement inOrder traversal?

You start traversal from root then goes to the left node, then again goes to the left node until you reach a leaf node. At that point in time, you print the value of the node or mark it visited and moves to right subtree. Continuing the same algorithm until all nodes of the binary tree are visited.

What is the meaning of non-recursive?

A non-recursive formula is a formula for a sequence that does not itself depend on any other terms in the sequence. In other words, the only variable you will need to plug in is the index of the sequence. For instance, S_n = n²

What is recursive traversal?

In a postorder traversal, we recursively do a postorder traversal of the left subtree and the right subtree followed by a visit to the root node. Let’s look at some examples that illustrate each of these three kinds of traversals.

#### What is Postorder transversal algorithm?

Edpresso Team. Tree traversal refers to visiting all the nodes of a tree exactly once. Visiting means doing something to the node. It can be as basic as printing the node. Post-order traversal is one of the multiple methods to traverse a tree.

#### How do I get Postorder?

Write an efficient algorithm to find postorder traversal on a given binary tree from its inorder and preorder sequence. A simple solution would be to construct the binary tree from the given inorder and preorder sequences and then print the postorder traversal by traversing the tree.

What is the difference between complete and full binary tree?

A full binary tree (sometimes proper binary tree or 2-tree) is a tree in which every node other than the leaves has two children. A complete binary tree is a binary tree in which every level, except possibly the last, is completely filled, and all nodes are as far left as possible.

How do I print inorder without recursion?

## Is there a non recursive algorithm for postorder traversal?

Objective: Given a binary tree, write a non recursive or iterative algorithm for postorder traversal. Earlier we have seen “ What is postorder traversal and recursive algorithm for it “, In this article we will solve it with iterative/Non Recursive manner.

## How to traverse a binary tree without recursion?

Inorder Tree Traversal without Recursion. Using Stack is the obvious way to traverse tree without recursion. Below is an algorithm for traversing binary tree using stack. See this for step wise step execution of the algorithm.

How is a preorder traversal of a binary tree performed?

Preorder traversal can also be performed using a non-recursive or iterative algorithm. In order to backtrack up the tree from a node to its parent, we use a stack. In an inorder traversal of a binary tree, we traverse one subtree of a node, then “visit” the node, and then traverse its other subtree.

What’s the difference between iterative and recursive traversal?

The difference is that a recursive way uses the call stack whereas an iterative way uses an explicit stack (the stack data structure). What this leads to are two things: 1) If it is a large tree, a recursive way can cause stack overflow. 2) With an iterative approach, you can stop somewhere in the middle of the traversal.