ET99资料

对编译器pl0代码进行扩展，具有if-else for，until ，注释功能。(the expendation of the simple complier of pl0, it does support if-else ,for,(**) funcyion ect. )

有关算术编码对文本压缩的程序在c++环境中实现(about arithmetic compressed)

说明：  用visual c++ 写的des加密算法演示 (with visual c write des encryption algorithm demo)

本源代码，综合了DES，RSA,MD5等几种加密的方法于同一工程中，可以让读者对各种加密方法的实现通过代码实现过程的比较，更好的理解几种软件加密方法(Source code, a combination of DES, RSA, MD5 encryption method, such as several in the same project, will allow readers to a variety of encryption methods to achieve the realization of the process through code comparison, a better understanding of several software encryption methods)

一个袖珍的vc++加密软件，同时还可以解密，加密文件的范围挺大的，几乎所有文件都可以加密，输入密码并解密，好像不是真正意义的加密，只不过是用文件额外加密的方法进行加密，较早时候的程序，不过编译还是顺利的。 (A pocket-sized vc++ encryption software, but also can decrypt encrypted files the scope of getting bigger, almost all the files can be encrypted, enter the password and decrypt the encryption does not seem real, but the file is an additional method of encryption to encrypt Earlier procedures, but the compiler is still smooth.)

说明：  编制程序，将输入的一行字符以加密的形式输出，然后将其解密，解密的字符串序列与输入的正文相比较，吻合时输出解密的正文，否则解密失败。 加密时，将每个字符的ascii码依次反复加上“4962873”中的数字，并在32（‘’）~122（‘z’）之间作模运算。解密与加密的顺序相反。例如输入正文“the result of 3 and 2 is not 8” 结果为： (Programming, the input line character output in an encrypted form, and then decrypted, the decrypted text sequence of characters compared with the input, output to decrypt the body of the agreement, otherwise the decryption failed. Encryption, ascii code of each character in turn repeatedly with &quot 4962873&quot in the figures, and 32 (' ' )~ 122 (' z' ) as a model between the operations. Decryption and encryption in reverse order. For example, enter the text &quot the result of 3 and 2 is not 8&quot results:)

Base64的编码程序 基于VC++编写的(Base64 encoding program written with VC++)

说明：  构建了一个词法分析器 能识别相应的字，方便理解词法分析的过程(To build a lexical analyzer to identify the appropriate words to facilitate understanding of the process of lexical analysis)

这里给出的源代码huffman.zip用8种不同的方式实现了Huffman编码算法。这些代码意在演示不同Huffman算法的实现原理，比较算法执行效率的差别，但并没有针对实际应用环境的需求，做更多的空空空间或效率优化。全部代码以C++语言开发，为了更容易地实现各种数据结构，代码中大量应用了标准C++库与模板技术。——总之，这些代码的作用在于示例与演示；如果大家想把这些代码应用在实际应用中，可能还需要 (The given here source code huffman.zip eight different ways to achieve the Huffman coding algorithm. These codes are intended to demonstrate different Huffman algorithm implementation principle, the difference of the algorithm execution efficiency, but does not demand for practical application environment, do more empty space or efficiency optimization. The entire code C++ language development code in order to make it easier to achieve a variety of data structures, a large number of applications the standard C++ library template.- In short, these code examples and demonstration If we want the code used in practical applications may also need)

自己写的一份RSA算法。可正常执行。控制台程序。(Write your own copy of the RSA algorithm. Can be performed normally. Console program.)