摘要： 题目如下： Given a binary tree root and an integer target, delete all the leaf nodes with value target. Note that once you delete a leaf node with value ta 阅读全文

摘要： 题目如下： Given a string s. Return all the words vertically in the same order in which they appear in s.Words are returned as a list of strings, complete 阅读全文

摘要： 题目如下： Given a positive integer num consisting only of digits 6 and 9. Return the maximum number you can get by changing at most one digit (6 becomes 9 阅读全文