mysql 数据 更新 插入 增加 删除

数据

 

mysql 用户与权限管理

用户与权限管理

 

mysql 查询 select 视图 连接 拼接 分组 组合查询

查询 select 视图 连接 拼接 分组 组合查询

 

创建计算字段

 

分组查询

 

子查询 和 表联结

 

组合查询

 

视图

 

mysql 登陆及常用命令

登陆及常用命令

 

mysql 约束

mysql 约束

[ ] 表示内容是可选填,不填则默认是数据库自动分配名字

 

mysql 使用函数

mysql 使用函数

 

设置mysql数据库中默认编码方式utf8

查看mysql数据库中默认编码方式

 

设置mysql数据库中默认编码方式

 

Host ‘xxx.xx.xxx.xxx’ is not allowed to connect to this MySQL server mysql拒绝远程连接解决方案

Host ‘xxx.xx.xxx.xxx’ is not allowed to connect to this MySQL server mysql拒绝远程连接解决方案

1.问题产生原因 :mysql默认只支持本地连接

 

2.解决方案:放开远程连接权限

 

java反射整理

java反射

可以通过某个类或者对象获得当前类的信息

例如存在Person类, p为实例化的对象,获得Class类c

获的 c 的属性

获得c的构造器

获得c的普通方法

1127 ZigZagging on a Tree(30 分)

1127 ZigZagging on a Tree(30 分) Suppose that all the keys in a binary tree are distinct positive integers. A unique binary tree can be determined by a given pair of postorder and inorder traversal sequences. And it is a simple standard routine to print the numbers in level-order. However, if you think the problem is too simple, then you are too naive. This time you are supposed to print the numbers in “zigzagging order” — that is, starting from the root, print the numbers level-by-level, alternating between left to right and right to left. For example, for the following tree you must output: 1 11 5 8 17 12 20 15.

zigzag.jpg

Input Specification: Each input file contains one test case. For each case, the first line gives a positive integer N (≤30), the total number of nodes in the binary tree. The second line gives the inorder sequence and the third line gives the postorder sequence. All the numbers in a line are separated by a space.

Output Specification: For each test case, print the zigzagging sequence of the tree in a line. All the numbers in a line must be separated by exactly one space, and there must be no extra space at the end of the line.

Sample Input: 8 12 11 20 17 1 15 8 5 12 20 17 11 15 8 5 1 Sample Output: 1 11 5 8 17 12 20 15