leetcode刷题笔记(Golang)--94. Binary Tree Inorder Traversal

94. Binary Tree Inorder Traversal

Given a binary tree, return the inorder traversal of its nodes’ values.

Example:

Input: [1,null,2,3]
1

2
/
3

Output: [1,3,2]
Follow up: Recursive solution is trivial, could you do it iteratively?

func inorderTraversal(root *TreeNode) []int {
	if root == nil {
		return []int{}
	}
	res := []int{}
	if root.Left != nil {
		res = append(res, inorderTraversal(root.Left)...)
	}
	res = append(res, root.Val)
	if root.Right != nil {
		res = append(res, inorderTraversal(root.Right)...)
	}
	return res  
}