Hello friends!

And, welcome to another tutorial on GeeksforGeeks. In this video we are going to understand the

program which calculates depth of a full binary tree from preorder..First, let us take

an example.. We start from depth 0..The preorder is given

as a string with two possible characters.‘l’ denotes the leaf ‘n’

denotes internal node The given tree can be seen as a full binary

tree where every node has 0 or two children. The two children of a node can ‘n’

or ‘l’ or mix of both. .. Now, let us see the algorithm which will

assist us in this Let us also have a sample tree to test our

algorithm.. We pass the tree array, and n to function

findDepth…n are the number of nodes in the binary

tree. We take another variable index which we initialize

to 0 We pass the tree array, n and index to findDepthRec

Function.. As index is not greater than n or the element

at index is not l, we increment index.. So, index

will be equal to 1 We calculate height of left subtree… So,

we call the findDepthRec function with index as 1..

Using a call stack.. As index is not>=n.. We check if the

element in the tree array at index 1 is l.. As it is true, we

return 0 Now we calculate height of right subtree.

So, we increment index.. Next, we pass tree, n and index As index is not>=n and the element at

index 2 in tree array is not l.. We increment index. Next, we call for the findDepthRec function

with index=3 As index is not greater than n but element

at index 3 in array tree is l, we return 0 We increment index Next, we calculate hieght of right subtree..

So, we pass index as 4. As element at index 4 is l, we return 0 We return max of left and right +1, so, we

return 1 Again, we return max of left,right +1.. As

right is greater>left, so we return 1+1=2 So this is the depth of this binary tree.

With this we come to an end of this tutorial. For any doubts or suggestions please leave

them in the comment section below. Thanks for watching!