1,创建一个复数类complex，以复数进行数学运算 2.创建银行账号Account类，实现存款(balance)的存(deposit)、取(withdraw)和查询(getbalance)等功能 3.编程定义一个接口，实现三个数中求最小值和最大值的方法，并将程序存放在mymaths包中 4.修改5.7.2案例1中的部分设计：①设计和实现Clipher类的一个子类，它实现如下的加密规则：在字母表中的每个字母用反字母表中的相应位置的字母来代替，如a用z来代替，b用y来代替等。②修改Transpose.encode()方法使其采用旋转而不是反转。也就是说，通过旋转一个字符，如“hello”则旋转为“ohell”-1, create a complex class complex mathematical operations in the plural　2 Account class to create a bank account, deposit (balance) deposit (deposit) take (withdraw) and query (getbalance) function　programming defined a interface, three numbers for the minimum and maximum values, and stored procedures mymaths package　4. modify 5.7.2 Case 1 part of the design: (1) design and implementation of a subclass of Clipher class, it encryption rules as follows: for each letter in the alphabet, the letter of the corresponding positions in the anti-alphabet instead, such as a Z instead b with y instead. Render ② to modify Transpose.encode () by using a rotary rather than inverted. That is to say, by the rotation of a character, such as " hello"　rotation " ohell"