이진 검색 트리(BST) - 삽입

<script>

// javascript program to demonstrate insert 
// operation in binary search tree
// BST node
class Node
{
    constructor()
    {
        this.key = 0;
        this.left = null;
        this.right = null;
    }
};

// Utility function to create a new node
function newNode(data)
{
    var temp = new Node();
    temp.key = data;
    temp.left = null;
    temp.right = null;
    return temp;
}

// A utility function to insert a new
// Node with given key in BST
function insert(root, key)
{

    // Create a new Node containing
    // the new element
    var newnode = newNode(key);

    // Pointer to start traversing from root and
    // traverses downward path to search
    // where the new node to be inserted
    var x = root;

    // Pointer y maintains the trailing
    // pointer of x
    var y = null;

    while (x != null)
    {
        y = x;
        if (key < x.key)
            x = x.left;
        else
            x = x.right;
    }

    // If the root is null i.e the tree is empty
    // The new node is the root node
    if (y == null)
        y = newnode;

    // If the new key is less than the leaf node key
    // Assign the new node to be its left child
    else if (key < y.key)
        y.left = newnode;

    // else assign the new node its right child
    else
        y.right = newnode;

    // Returns the pointer where the
    // new node is inserted
    return y;
}

// A utility function to do inorder
// traversal of BST
function Inorder(root)
{
    if (root == null)
        return;
    else
    {
        Inorder(root.left);
        document.write( root.key +" ");
        Inorder(root.right);
    }
}

// Driver code
/* Let us create following BST
        50
    / \
    30 70
    / \ / \
20 40 60 80 */
var root = null;
root = insert(root, 50);
insert(root, 30);
insert(root, 20);
insert(root, 40);
insert(root, 70);
insert(root, 60);
insert(root, 80);
// Print inorder traversal of the BST
Inorder(root);

// This code is contributed by itsok.
</script>