Binary Search Tree - Postorder logic

Posted by daveb on Stack Overflow See other posts from Stack Overflow or by daveb
Published on 2012-03-13T16:44:42Z Indexed on 2012/03/22 17:29 UTC
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logic

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binary-trees

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binary-search

I am looking at implementing code to work out binary search tree. Before I do this I was wanting to verify my input data in postorder and preorder.

I am having trouble working out what the following numbers would be in postorder and preorder I have the following numbers 4, 3, 14 ,8 ,1, 15, 9, 5, 13, 10, 2, 7, 6, 12, 11, that I am intending to put into an empty binary tree in that order.

The order I arrived at for the numbers in POSTORDER is

2, 1, 6, 3, 7, 11, 12, 10, 9, 8, 13, 15, 14, 4. Have I got this right?

I was wondering if anyone here would be able to kindly verify if the postorder sequence I came up with is indeed the correct sequence for my input i.e doing left subtree, right subtree and then root.

The order I got for pre order (Visit root, do left subtree, do right subtree) is 4, 3, 1, 2, 5, 6, 14 , 8, 7, 9, 10, 12, 11, 15, 13. I can't be certain I got this right. Very grateful for any verification.

Many Thanks

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