# How can use this sequence to create a binary search tree?

• I am try to solve this problem, but wrong with this case

Input: {68,41,#,-85,#,-73,-49,-98,#,#,#,-124}
Output: {68,-73,#,-85,#,41,-49,-98,#,#,#,-124}
Expected: {68,41,#,-73,#,-85,-49,-98,#,#,#,-124}

I think all sequence is the pre order traverse sequence, but i don't think expected can create a normal binary search tree

• That's because the inputs and outputs are written using a modified level-order traversal, not preorder. The # means end of line of descent, not just "This is a null element." This is actually shown in several tree problems under the "confused what "{1,#,2,3}" means? > read more on how binary tree is serialized on OJ." link.

Input:

``````            68
/
41
/
-85
/  \
-73 -49
/
-98
/
-124
``````

The expected answer has -85 and -73 swapped and so looks like this:

``````            68
/
41
/
-73
/  \
-85 -49
/
-98
/
-124
``````

Yours, on the other hand, swapped 41 and -73 and so looks like this:

``````            68
/
-73
/
-85
/  \
41  -49
/
-98
/
-124
``````

• thank you very much

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