From fba519621a42435fcffdf538fd5ea93a42fca87c Mon Sep 17 00:00:00 2001
From: Matt <50872444+MattDClarke@users.noreply.github.com>
Date: Mon, 24 Jan 2022 21:33:03 +0200
Subject: [PATCH] fix(curriculum): added test using a tree that is not a binary
 search tree (#44775)

---
 .../check-if-binary-search-tree.md            | 20 ++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/curriculum/challenges/english/10-coding-interview-prep/data-structures/check-if-binary-search-tree.md b/curriculum/challenges/english/10-coding-interview-prep/data-structures/check-if-binary-search-tree.md
index ddaf38f231..4a6f0bb9b5 100644
--- a/curriculum/challenges/english/10-coding-interview-prep/data-structures/check-if-binary-search-tree.md
+++ b/curriculum/challenges/english/10-coding-interview-prep/data-structures/check-if-binary-search-tree.md
@@ -39,6 +39,24 @@ assert(
 );
 ```
 
+`isBinarySearchTree()` should return false when checked with a tree that is not a binary search tree.
+
+```js
+assert(
+  (function () {
+    var test = false;
+    if (typeof BinarySearchTree !== 'undefined') {
+      test = new BinarySearchTree();
+    } else {
+      return false;
+    }
+    test.push(1);
+    test.root.left = new Node(1);
+    return isBinarySearchTree(test) == false;
+  })()
+);
+```
+
 # --seed--
 
 ## --after-user-code--
@@ -114,7 +132,7 @@ function isBinarySearchTree(tree) {
     function checkTree(node) {
       if (node.left != null) {
         const left = node.left;
-        if (left.value > node.value) {
+        if (left.value >= node.value) {
           isBST = false;
         } else {
           checkTree(left);