//?crc1.cpp?:?Defines?the?entry?point?for?the?console?application.
//http://hi.baidu.com/yanzi52351
//yanzi52351@126.com

#include?“stdafx.h“
#include?
#include?

unsigned?long??int?crc32_table[256];
unsigned?long?int?ulPolynomial?=?0x04c11db7;

unsigned?long?int?Reflect（unsigned?long?int?ref?char?ch）{
	unsigned?long?int?value=0;
	int?i;?
	for（i?=?1;?i?		if（ref?&?1）
			value?|=?1?<		ref?>>=?1;
	}
	return?value;
}


void?init_crc32_table（）{
	unsigned?long?int?crctemp;
	unsigned?long?int?t1t2;
	unsigned?long?int?flag;
	int?ij;
	for（i?=?0;?i?<=?0xFF;?i++）{
		temp=Reflect（i?8）;
		crc32_table[i]=?temp<		for?（j?=?0;?j?			
			flag=crc32_table[i]&0x80000000;
			t1=（crc32_table[i]?<			if（flag==0）
				t2=0;
			else
				t2=ulPolynomial;
			crc32_table[i]?=t1^t2?;
			
		}
		crc=crc32_table[i];
		crc32_table[i]?=?Reflect（crc32_table[i]?32）;
	}
	return;
	
}

unsigned?long?GenerateCRC32（char*?DataBufunsigned?long??len）???//crc32生成函數
{???
	unsigned?long??oldcrc32;???
	unsigned?long??crc32;???
	unsigned?long??oldcrc;???
	unsigned?int??charcnt;???
	char?ct;???
	oldcrc32=0x00000000;???//初值為0???
	charcnt=0;???
	while（len--）
	{???
		t=?（oldcrc32>>24）&0xFF;???????//要移出的字節的值???
		oldcrc=crc32_table[t];???????????????????//根據移出的字節的值查表???
		c=DataBuf[charcnt];?????????????????????//新移進來的字節值???
		oldcrc32=（oldcrc32<<8）|c;???????//將新移進來的字節值添在寄存器末字節中???
		oldcrc32=oldcrc32^oldcrc;???????????//將寄存器與查出的值進行xor運算???
		charcnt++;???
	}???
	crc32=oldcrc32;???
	return???crc32;???
??}?

int?main（int?argc?char*?argv[]）
{
	char?test[6]={‘b‘‘c‘‘d‘‘d‘‘d‘‘r‘};
	init_crc32_table（）;?????????//先生成
	GenerateCRC32（testsizeof（test））;

	return?0;
}

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????1863??2010-05-20?15:35??crc1\crc1.cpp

?????文件???????4512??2010-05-19?20:44??crc1\crc1.dsp

?????文件????????516??2010-05-19?20:44??crc1\crc1.dsw

?????文件??????50176??2010-05-20?15:35??crc1\crc1.ncb

?????文件??????48640??2010-05-20?15:35??crc1\crc1.opt

?????文件???????1390??2010-05-20?15:34??crc1\crc1.plg

?????文件????????202??2010-05-20?15:35??crc1\crc1.positions

?????文件?????172120??2010-05-20?15:34??crc1\Debug\crc1.exe

?????文件???????1196??2010-05-19?20:44??crc1\ReadMe.txt

?????文件????????291??2010-05-19?20:44??crc1\StdAfx.cpp

?????文件????????769??2010-05-19?20:44??crc1\StdAfx.h

?????目錄??????????0??2010-05-20?15:37??crc1\Debug

?????目錄??????????0??2010-05-20?15:35??crc1

?????文件????????119??2010-05-20?15:07??我的空間.url

?????文件????????125??2010-05-20?15:08??說明.url

-----------?---------??----------?-----??----

???????????????281919????????????????????15