Add solution #94

Author: JoshCrozier

Diff for: README.md

@@ -40,6 +40,7 @@
 74|[Search a 2D Matrix](./0074-search-a-2d-matrix.js)|Medium|
 83|[Remove Duplicates from Sorted List](./0083-remove-duplicates-from-sorted-list.js)|Easy|
 88|[Merge Sorted Array](./0088-merge-sorted-array.js)|Easy|
+94|[Binary Tree Inorder Traversal](./0094-binary-tree-inorder-traversal.js)|Easy|
 118|[Pascal's Triangle](./0118-pascals-triangle.js)|Easy|
 119|[Pascal's Triangle II](./0119-pascals-triangle-ii.js)|Easy|
 121|[Best Time to Buy and Sell Stock](./0121-best-time-to-buy-and-sell-stock.js)|Easy|

Diff for: solutions/0094-binary-tree-inorder-traversal.js

@@ -0,0 +1,37 @@
+/**
+ * 94. Binary Tree Inorder Traversal
+ * https://leetcode.com/problems/binary-tree-inorder-traversal/
+ * Difficulty: Easy
+ *
+ * Given the root of a binary tree, return the inorder traversal of its nodes' values.
+ */
+
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number[]}
+ */
+var inorderTraversal = function(root) {
+  const result = [];
+  const stack = [];
+
+  while (root || stack.length) {
+    if (root) {
+      stack.push(root);
+      root = root.left;
+    } else {
+      const { val, right } = stack.pop();
+      result.push(val);
+      root = right;
+    }
+  }
+
+  return result;
+};