Save in preorder, tagging each node with two bits indicating if that node
has a left and right subtree.
Then rebuild like this:
Tree rebuild()
{
Tree result = readNode();
Tree->left = hasLeftSubtree ? rebuild() : 0;
Tree->right = hasRightSubtree ? rebuild() : 0;
return result;
}
On Friday, November 8, 2013 1:00:35 PM UTC-5, atul007 wrote:
>
> @don : it is not BST , it is binary tree ...so your approach will
> not work in this case.
>
> @kumar : save pre-order and in-order traversal with some delimiter in
> b/w traversals.
>
> pre-order : a b c d e
> in-order : c b e a d
>
> write in file :-
>
> a b c d e # c b e a d
>
> now use pre-order and in-order traversal to re-create binary tree.
>
> 2) consider null node as "#" ..now write in file preorder traversal.
>
> for eg : a b c # # # d # #
>
> 3) save level order traversal of binary tree, where each level uses
> "#" to distinguish between levels and "*" to mark null nodes
> eg : a # b c # e *
> a - level 1
> b c - level 2
> e NULL - level 3
>
> shortcoming in 2 and 3 is use of character that can be part of tree
> itself.So if node can contain "#" then you have to use some other
> character to distinguish.
>
> for solution 1 , you can write traversal in 2 lines instead of using "#"
>
> On 11/8/13, Vishnu <[email protected] <javascript:>> wrote:
> > 1) save the nodes(value, left and right pointer) in pre-order traversal
> > 2) also save pointers of all node in same order
> >
> > to restore
> > 1) create new N nodes
> > 2) do pointer mapping from old -> new
> > 3) restore nodes and replace old pointers to new
> >
> >
> > On Fri, Nov 8, 2013 at 8:50 PM, Don <[email protected] <javascript:>>
> wrote:
> >
> >> Save it in pre-order.
> >> Rebuild by inserting nodes in the order they occur in the file.
> >>
> >>
> >> On Friday, November 8, 2013 8:33:19 AM UTC-5, kumar raja wrote:
> >>>
> >>> What is the effective way to save and restore the binary trees to
> files
> >>> effectively?
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Regards,
> >>> Kumar Raja.
> >>>
> >> --
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> >> email to [email protected] <javascript:>.
> >>
> >
> >
> >
> > --
> > Thanks,
> > Vishnu
> >
> > --
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>
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