Given a binary tree, return the level order traversal of its nodes’ values. (ie, from left to right, level by level).

Given a binary tree, return the zigzag level order traversal of its nodes’ values. (ie, from left to right, then right to left for the next level and alternate ...

Given a binary tree, return the bottom-up level order traversal of its nodes’ values. (ie, from left to right, level by level from leaf to root).

Reverse a linked list from position m to n. Do it in-place and in one-pass.

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

SET是一个字符串对象，可以有零或多个值，其值来自表创建时规定的允许的一列值。指定包括多个SET成员的SET列值时各成员之间用逗号(‘,’)间隔开。这样SET成员值本身不能包含逗号。...

1.单独引用复合索引里非第⼀位置的索引列 假如有INDEX(a,b,c)， 当条件为a或a,b或a,b,c时都可以使用索引，

如果是CHAR，VARCHAR类型，length可以小于字段实际长度；如果是BLOB和TEXT类型，必须指定 length。

Given two binary trees, write a function to check if they are the same or not.

最近用了Optional实现了一段逻辑，想不到居然翻车了。看了源码之后才恍然大悟，不过翻车的不是我一个人，很多人都说自己在这个地方翻过车，其中不乏一些大佬级的人物。...