在二叉搜索树中插入问题

Question

I am getting confused on my binary search algorithm. I have to insert the following integers into an empty binary tree in the given order using put(): 4,1,3,5,2. Im not 100 percent sure if I went about the right way in doing this. Here is what I did.. My main part of confusion came up when I had to insert the 2. I just want to make sure I am doing this correctly. Thanks all.

       4
      / \
     1   5
    /\   
      3
      /
     2

Answer 1

You are spot on, 2 < 4 and 2 > 1 and finally 2 < 3

The Rules for Binary Search Tree Insertion are as follows:

If the key to insert is smaller than the current value , insert the key into the current values left subtree.

If the key to insert is larger than the current value , insert the key into the current values right subtree.

If the key is a duplicate value you will not insert.

It may seem to you that your answer is wrong because you may think it looks weird to you as a human to have 2 as a child of 3. Dont worry about that oddity. Just trust the algorithm, follow the rules all the time, and your insertion will work.

I am posting a link you should take a look at. It gives an excellent visualization of many data structures, and will help you if you run into a problem like this again. The site allows you to build your own binary search tree in whatever order you would like to insert.

As a side note: The site also offers many other data structure visualizations should you have a similar question on a different data structure in the future.

Binary Search Tree Visualization