Subtree of Another Tree

Author: ShyamMahajan

readme.md

@@ -33,3 +33,4 @@
 29. Maximum Depth of Binary Tree - (https://leetcode.com/problems/maximum-depth-of-binary-tree/)
 30. Binary Tree Maximum Path Sum - (https://leetcode.com/problems/binary-tree-maximum-path-sum/) (H)
 31. Binary Tree Level Order Traversal - (https://leetcode.com/problems/binary-tree-level-order-traversal/) (M)
+32. Subtree of Another Tree - (https://leetcode.com/problems/subtree-of-another-tree/) (E)

subtree-of-another-tree.js

@@ -0,0 +1,43 @@
+/***Given the roots of two binary trees root and subRoot, return true if there is a subtree of root with the same structure and node values of subRoot and false otherwise.
+
+A subtree of a binary tree tree is a tree that consists of a node in tree and all of this node's descendants. The tree tree could also be considered as a subtree of itself. */
+/**
+ * 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
+ * @param {TreeNode} subRoot
+ * @return {boolean}
+ */
+ var isSubtree = function(root, subRoot) {
+ if (!subRoot) {
+ return true;
+ }
+ 
+ if (!root) {
+ return false;
+ }
+ 
+ if (isSameTree(root, subRoot)) {
+ return true;
+ }
+ 
+ return isSubtree(root.left, subRoot) || isSubtree(root.right, subRoot);
+ };
+ 
+ function isSameTree(p, q) {
+ if (!p && !q) {
+ return true;
+ }
+ 
+ if (!p || !q || p.val !== q.val) {
+ return false;
+ }
+ 
+ return isSameTree(p.left, q.left) && isSameTree(p.right, q.right)
+ }