Add solution #872

Author: JoshCrozier

0872-leaf-similar-trees.js

@@ -0,0 +1,45 @@
+/**
+ * 872. Leaf-Similar Trees
+ * https://leetcode.com/problems/leaf-similar-trees/
+ * Difficulty: Easy
+ *
+ * Consider all the leaves of a binary tree, from left to right order, the values of
+ * those leaves form a leaf value sequence.
+ *
+ * For example, in the given tree above, the leaf value sequence is (6, 7, 4, 9, 8).
+ *
+ * Two binary trees are considered leaf-similar if their leaf value sequence is the same.
+ *
+ * Return true if and only if the two given trees with head nodes root1 and root2 are
+ * leaf-similar.
+ */
+
+/**
+ * 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} root1
+ * @param {TreeNode} root2
+ * @return {boolean}
+ */
+var leafSimilar = function(root1, root2) {
+  return traverse(root1, []).toString() === traverse(root2, []).toString();
+};
+
+function traverse(root, result) {
+  if (!root.left && !root.right) {
+    result.push(root.val);
+  }
+  if (root.left) {
+    traverse(root.left, result);
+  }
+  if (root.right) {
+    traverse(root.right, result);
+  }
+  return result;
+}

README.md

@@ -257,6 +257,7 @@
 844|[Backspace String Compare](./0844-backspace-string-compare.js)|Easy|
 846|[Hand of Straights](./0846-hand-of-straights.js)|Medium|
 867|[Transpose Matrix](./0867-transpose-matrix.js)|Easy|
+872|[Leaf-Similar Trees](./0872-leaf-similar-trees.js)|Easy|
 876|[Middle of the Linked List](./0876-middle-of-the-linked-list.js)|Easy|
 884|[Uncommon Words from Two Sentences](./0884-uncommon-words-from-two-sentences.js)|Easy|
 890|[Find and Replace Pattern](./0890-find-and-replace-pattern.js)|Medium|