Table of Contents

- 1 How do you get an element of a child?
- 2 How can you tell how many children an element has?
- 3 How do you create a child’s node?
- 4 What is a parent and child node?
- 5 What is lowest common ancestor in a BST?
- 6 Who is the common ancestor?
- 7 Is a graph with 1 node a tree?
- 8 Can a binary tree have 1 child?
- 9 What is height of a BST?
- 10 Which data structure is used in printer?

## How do you get an element of a child?

HTML DOM childNodes Property

- Get a collection of the element’s child nodes: var c = document.
- Find out how many child nodes a <div> element has:
- Change the background color of the second child node (index 1) of a <div> element:
- Get the text of the third child node (index 2) of a element:

**How do I get child elements in CSS?**

The child combinator ( > ) is placed between two CSS selectors. It matches only those elements matched by the second selector that are the direct children of elements matched by the first. Elements matched by the second selector must be the immediate children of the elements matched by the first selector.

**What is a child element in HTML?**

Child nodes (or children) – elements that are direct children. In other words, they are nested exactly in the given one. For instance, and are children of <html> element.

### How can you tell how many children an element has?

How to check if an element has any children in JavaScript ?…Approach:

- Select the Parent Element.
- Use one of the firstChild, childNodes. length, children. length property to find whether element has child or not.
- hasChildNodes() method can also be used to find the child of the parent node.

**How do I check if a div has a child?**

To check if an HTML element has child nodes, you can use the hasChildNodes() method. This method returns true if the specified node has any child nodes, otherwise false . Whitespace and comments inside a node are also considered as text and comment nodes.

**What is a child node?**

Child: A child node is a node extending from another node. For example, a computer with internet access could be considered a child node of a node representing the internet. The inverse relationship is that of a parent node. If node C is a child of node A, then A is the parent node of C.

## How do you create a child’s node?

HTML DOM appendChild() Method

- Append an item in a list: var node = document.
- Move a list item from one list to another: var node = document.
- Create a
element and append it to a element: var para = document.

- Create a
element with some text and append it to the end of the document body:

**What’s the difference between childNodes and children?**

The children property returns a collection of an element’s child elements, as an HTMLCollection object. The difference between this property and childNodes, is that childNodes contain all nodes, including text nodes and comment nodes, while children only contain element nodes.

**What is the parent of a node?**

A node that has a child is called the child’s parent node (or superior). A node has at most one parent, but possibly many ancestor nodes, such as the parent’s parent. Child nodes with the same parent are sibling nodes.

### What is a parent and child node?

Any subnode of a given node is called a child node, and the given node, in turn, is the child’s parent. Sibling nodes are nodes on the same hierarchical level under the same parent node. Nodes higher than a given node in the same lineage are ancestors and those below it are descendants.

**How can we identify children in binary tree?**

Program to find number of only child in a binary tree in python

- if root is null, then. return 0.
- d := a double ended queue.
- insert root at the end of d.
- count := 0.
- while d is not empty, do. current := left element of d and delete left element. if left of current is not null, then. insert left of current into d.
- return count.

**How do I find the parent of a node?**

Approach: Write a recursive function that takes the current node and its parent as the arguments (root node is passed with -1 as its parent). If the current node is equal to the required node then print its parent and return else call the function recursively for its children and the current node as the parent.

## What is lowest common ancestor in a BST?

Let T be a rooted tree. The lowest common ancestor between two nodes n1 and n2 is defined as the lowest node in T that has both n1 and n2 as descendants (where we allow a node to be a descendant of itself).

**What is child node in data structure?**

Child. In a tree data structure, the node which is descendant of any node is called as CHILD Node. In simple words, the node which has a link from its parent node is called as child node. In a tree, any parent node can have any number of child nodes.

**What is an ancestor in binary tree?**

A node that is connected to all lower-level nodes is called an “ancestor”. The connected lower-level nodes are “descendants” of the ancestor node.

### Who is the common ancestor?

In biology and genealogy, the most recent common ancestor (MRCA), last common ancestor (LCA), or concestor of a set of organisms is the most recent individual from which all the organisms of the set are descended. The term is also used in reference to the ancestry of groups of genes (haplotypes) rather than organisms.

**What is a perfect tree?**

A perfect binary tree is a binary tree in which all interior nodes have two children and all leaves have the same depth or same level. A balanced binary tree is a binary tree structure in which the left and right subtrees of every node differ in height by no more than 1.

**What is a proper ancestor?**

proper ancestor of n. A proper ancestor of n is any node y such that node y is an ancestor of node n and y is not the same node as n. descendent of n. Any node y for which n is an ancestor of y. Every node is an descendent of itself.

## Is a graph with 1 node a tree?

2 Answers. For the former: yes, by most definitions, the one-vertex, zero-edge graph is a tree. For the latter: yes, all vertices of degree 1 are leaves. In general, which node you call the “root” is pretty much arbitrary.

**What is ancestor and descendant in tree?**

Besides the parent-child relationship, we can think of tree nodes having ancestors and descendants. An ancestor of a node is any other node on the path from the node to the root. • A descendant is the inverse relationship of ancestor: A node p is a descendant of a node q if and only if q is an ancestor of p.

**Can a single node be a tree?**

And as a concept, the definition of a tree simply involves a set of nodes, one of which is marked as the root, and edges connecting these nodes without cycles. There is nothing that requires that there is more than one node. So yes, a single node is a tree.

### Can a binary tree have 1 child?

A binary tree is a tree in which no node has more than two children, and every child is either a left child or a right child even if it is the only child its parent has. A full binary tree is one in which every internal node has two children.

**How many trees are possible with 10 nodes?**

It is 1014.

**What is the height of a tree with 1 node?**

According to Wikipedia, The height of a tree is the length of the path from the root to the deepest node in the tree. A (rooted) tree with only one node (the root) has a height of zero (or one).

## What is height of a BST?

The height of a binary tree is the height of the root node in the whole binary tree. In other words, the height of a binary tree is equal to the largest number of the edges from the root to the most distant leaf node. A similar concept in a binary tree is the depth of the tree.

**What is height in a tree data structure?**

Height of tree –The height of a tree is the number of edges on the longest downward path between the root and a leaf. So the height of a tree is the height of its root.

**What is difference between height and depth of a tree?**

The depth of a node is the number of edges from the node to the tree’s root node. The height of a node is the number of edges on the longest path from the node to a leaf.

### Which data structure is used in printer?

A computer’s operating system uses queue data structures to manage the computer’s resources. Here are some examples: the printer: the OS uses a “print queue” to hold the identities of the processes (executing user programs) that wish to use the printer.

**What is height of AVL tree?**

If there are n nodes in AVL tree, minimum height of AVL tree is floor(log2n). If there are n nodes in AVL tree, maximum height can’t exceed 1.44*log2n. If height of AVL tree is h, maximum number of nodes can be 2h+1 – 1.