Since you already know what a binary search tree is, this challenge will establish how it is you can tell that a tree is a binary search tree or not.
The main distinction of a binary search tree is that the nodes are ordered in an organized fashion. Nodes have at most 2 child nodes (placed to the right and/or left) based on if the child node's value is greater than or equal to (right) or less than (left) the parent node.
# --instructions--
In this challenge, you will create a utility for your tree. Write a JavaScript method `isBinarySearchTree` which takes a tree as an input and returns a boolean value for whether the tree is a binary search tree or not. Use recursion whenever possible.
# --hints--
Your Binary Search Tree should return true when checked with `isBinarySearchTree()`.
```js
assert(
(function () {
var test = false;
if (typeof BinarySearchTree !== 'undefined') {
test = new BinarySearchTree();
} else {
return false;
}
test.push(1);
test.push(5);
test.push(3);
test.push(2);
test.push(4);
return isBinarySearchTree(test) == true;
})()
);
```
# --seed--
## --after-user-code--
```js
BinarySearchTree.prototype.push = function(val) {
var root = this.root;
if (!root) {
this.root = new Node(val);
return;
}
var currentNode = root;
var newNode = new Node(val);
while (currentNode) {
if (val <currentNode.value){
if (!currentNode.left) {
currentNode.left = newNode;
break;
} else {
currentNode = currentNode.left;
}
} else {
if (!currentNode.right) {
currentNode.right = newNode;
break;
} else {
currentNode = currentNode.right;
}
}
}
};
```
## --seed-contents--
```js
var displayTree = (tree) => console.log(JSON.stringify(tree, null, 2));
function Node(value) {
this.value = value;
this.left = null;
this.right = null;
}
function BinarySearchTree() {
this.root = null;
}
function isBinarySearchTree(tree) {
// Only change code below this line
// Only change code above this line
}
```
# --solutions--
```js
var displayTree = (tree) => console.log(JSON.stringify(tree, null, 2));
