BFS

Breadth First Traversal or Level Order Traversal: As name suggests, in tree traversal, where in we are traversing the breadth of tree. In this traversal, we traverse all nodes across the breadth of binary tree. In level order traversal we perform following procedure:
Traverse the binary tree level by level
At each level we go left to right

Given binary tree in java, print binary tree in reverse order using level order traversal or breadth first search (BFS) non recursive algorithm (example).

We have to find the number of nodes in the binary tree. We will use the Level order traversal or Breadth first traversal to scan the complete binary tree. We have to travel at-least once to get the number of nodes in the binary tree.

Find number of non leaf nodes in binary tree with one child node breadth first search(BFS)/level order traversal(non-recursive) algorithm (example)

What is non leaf node in binary tree?
A node in a binary tree which has child node(s) is called non leaf node.
Non Leaf Node can be Node having one child or both children:
One child (Either left child or right child)
Two children (Both left child and right child)

What is leaf node in binary tree?
A node in a binary tree which do not have any child nodes is called leaf node. The leaf node do not have any children i.e. left and right reference both null. We have to count the number of leaf nodes in the binary tree. In other ways we need to find out all the nodes in the binary tree which do not have any children (both right node and left node null).
So as per our problem statement, we have to iterate over the binary tree and find the number of leaf nodes in the binary tree.

We are given the Binary Tree, we need to find the maximum element in the Binary Tree. Suppose we have following tree, As per the problem statement we have to iterate over the binary tree and find the maximum element in the binary tree.

What is level in binary tree?
As per the definition of binary tree is one, where each node has, at most, 2 children. Each node can have left and right child. The root of the tree, is at level 0. Root’s children are at level 1, etc.
As an example, consider the tree:

We have to calculate the sum of all the nodes in a binary tree. To get the sum of all nodes in binary tree, we need to traverse the whole binary tree and while traversing we can start adding the sum of each node.

Let us define the problem statement, before we start our discussion about calculating the height of binary tree. What is height of Binary tree? Conventionally, the longest path from root to deepest leaf node define the height of binary tree.

Binary tree traversal using level order traversal or breadth first search non recursive algorithm in java (example). Visit root to leaf node level wise.