Add solution #100

Author: JoshCrozier

README.md

@@ -60,6 +60,7 @@
 88|[Merge Sorted Array](./0088-merge-sorted-array.js)|Easy|
 94|[Binary Tree Inorder Traversal](./0094-binary-tree-inorder-traversal.js)|Easy|
 98|[Validate Binary Search Tree](./0098-validate-binary-search-tree.js)|Medium|
+100|[Same Tree](./0100-same-tree.js)|Easy|
 101|[Symmetric Tree](./0101-symmetric-tree.js)|Easy|
 102|[Binary Tree Level Order Traversal](./0102-binary-tree-level-order-traversal.js)|Medium|
 104|[Maximum Depth of Binary Tree](./0104-maximum-depth-of-binary-tree.js)|Easy|

solutions/0100-same-tree.js

@@ -0,0 +1,30 @@
+/**
+ * 100. Same Tree
+ * https://leetcode.com/problems/same-tree/
+ * Difficulty: Easy
+ *
+ * Given the roots of two binary trees p and q, write a function to check if they are
+ * the same or not.
+ *
+ * Two binary trees are considered the same if they are structurally identical, and
+ * the nodes have the same value.
+ */
+
+/**
+ * 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} p
+ * @param {TreeNode} q
+ * @return {boolean}
+ */
+var isSameTree = function(p, q) {
+  const hasSameValue = p !== null && q !== null && p.val === q.val;
+  const hasSameTree = hasSameValue && isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
+  return (p === null && q === null) || hasSameTree;
+};