Not understand how tree will be made?

#1

Can you explain how to buildtree from given string input?

#2

The input given is level order. You have to build the tree accordingly.
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.

You can refer this sample code https://ide.codingblocks.com/s/60835

#3

@pratyush63 ,These things I know but actually in this question input is given in the form of string which contains , [ ] and also null.I am asking for this case!

#4

You will have to remove [ and ] and then tokenize the string with comma as deliminator.Use strtok function. Then you can put the value of each node in an array.
Refer this https://www.youtube.com/watch?v=i2ljAWLey00 from 57:11

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#5

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