crc 字符串校验.cpp

这是CRC字符串校验的源码

// crc 字符串校验.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"

int   crc(const char   *ptr,   int   count) ;

int _tmain(int argc, _TCHAR* argv[])
{
	int ret;
	char jiaoyan[33] = {'y', 'y','r','e', 'd','e','r', 'w','e'};
	//string str = (string)jiaoyan;

	ret = crc(jiaoyan, 9);
	ret = crc(jiaoyan, 9);
		return 0;
}

int   crc(const char   *ptr,   int   count)  
{  
        int   crc   =   0,   i;  
        while   (--count   >=   0)   
		{  
                crc   =   crc   ^   (int)*ptr++   <<   8;  
                for   (i   =   0;   i   <   8;   ++i) 
				{
                        if   (crc   &   0x8000) 
						{
                                crc   =   crc   <<   1   ^   0x1021; 
						}
                        else 
						{
                                crc   =   crc   <<   1; 
						}
				}
         }  

         return   (crc   &   0xFFFF);  
}