Tree Left View Problem

#1

I am not able to do this question, i am not getting how to make a tree using level order.
Can you provide me with any kind of video or code?

#2

@minal.251298,

to create a binary tree from level order input, we can build this binary tree by maintaining a queue. Queue is used to maintain those nodes that are not yet processed.

Using a variable count to keep track of the number of children added for the current node.

First, create a root node, assign it as the current node. So starting from index 1 (index 0 is the root), as the count is 0, we add this node as left child of the current node. Increase count. If this node is not ‘-1’, add it to the queue.

Moving to the next index, the count is 1, so we add this as right child of current node, reset count to 0 and update current node (by assigning the current node as the first element in the queue). If this node is not ‘-1’, add it to the queue.

#3

Can u provide me code for that?

#4

@minal.251298,

https://ide.codingblocks.com/s/225063 This is a sample approach. Modify it according to your code. You can attempt the question and reply to me on this thread if you face any problem.

#5


Please check my code

#6

@minal.251298,
https://ide.codingblocks.com/s/225248 corrected code. Use a while loop for queue.

#7

And how we can pass an array in it?
like how we are going to take input

#8

@minal.251298,
you can take input in a arraylist and then convert that into an array

#9

Can you please provide me the code?

#10


Can i do this?

#11

@minal.251298,
Yes absolutely. Your code should be correct.