finish 0572

README.md

@@ -44,6 +44,7 @@ since 2021.10.10 / Benben
 - 0242.Valid Anagram
 - 0509.Fibonacci Number
 - 0543.Diameter of Binary Tree
+- 0572.Subtree of Another Tree
 - 0704.Binary Search
 - 0905.Sort Array By Parity
 - 1694.Reformat Phone Number

leetcode-easy/0572-subtree-of-another-tree.js

@@ -0,0 +1,35 @@
+/**
+ * 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 (root === null || subRoot === null) return false
+
+  const isSameTree = (n1, n2) => {
+    if (n1 === null && n2 === null) return true
+    if (n1 === null || n2 === null) return false
+    if (n1.val !== n2.val) return false
+    return isSameTree(n1.left, n2.left) && isSameTree(n1.right, n2.right)
+  }
+
+  const traverseRoot = (root, subRoot) => {
+    if (root === null) return subRoot === null
+    if (isSameTree(root, subRoot)) return true
+    return traverseRoot(root.left, subRoot) || traverseRoot(root.right, subRoot)
+  }
+
+  return traverseRoot(root, subRoot)
+};
+
+// 2022/05/21 done
+// Runtime: 74 ms, faster than 98.49% of JavaScript online submissions for Subtree of Another Tree.
+// Memory Usage: 49.6 MB, less than 18.31% of JavaScript online submissions for Subtree of Another Tree.