feat: #617

617.merge-two-binary-trees.js

@@ -0,0 +1,26 @@
+/*
+ * @lc app=leetcode id=617 lang=javascript
+ *
+ * [617] Merge Two Binary Trees
+ */
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val) {
+ *     this.val = val;
+ *     this.left = this.right = null;
+ * }
+ */
+/**
+ * @param {TreeNode} t1
+ * @param {TreeNode} t2
+ * @return {TreeNode}
+ */
+var mergeTrees = function(t1, t2) {
+  // 递归，由于树是一种递归的数据结构，因此递归是符合直觉且比较简单的
+  if (t1 === null) return t2;
+  if (t2 === null) return t1;
+  t1.val += t2.val;
+  t1.left = mergeTrees(t1.left, t2.left);
+  t1.right = mergeTrees(t1.right, t2.right);
+  return t1;
+};