Data Structures: Add a New Element to a Binary Search Tree

Data Structures/bstAddElement.js

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+// https://www.freecodecamp.org/learn/coding-interview-prep/data-structures/add-a-new-element-to-a-binary-search-tree
+
+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;
+  // Only change code below this line
+  this.add = (item) => {
+    const newNode = new Node(item);
+    if (this.root === null) {
+      this.root = newNode;
+    }
+    let parentNode = null;
+    let nodeBranch = "left";
+    let node = this.root;
+    while (node !== null) {
+      parentNode = node;
+      if (node.value == item) {
+        return null;
+      } else if (node.value < item) {
+        nodeBranch = "right";
+        node = node.right;
+      } else {
+        nodeBranch = "left";
+        node = node.left;
+      }
+    }
+    parentNode[nodeBranch] = newNode;
+  };
+  // Only change code above this line
+}