摘要: Given a binary tree, return the preorder traversal of its nodes' values. For example:Given binary tree [1,null,2,3], 1 \ 2 / 3 return [1,2,3]. Note: R 阅读全文
posted @ 2018-01-31 00:00 乐乐章 阅读(142) 评论(0) 推荐(0) 编辑