#include "stdafx.h"
#include <iostream>
#include <assert.h>

int myStrCmp(const char *pStr1,const char *pStr2)  
{  
	while(NULL != pStr1 && NULL != pStr2)  
	{  
		while(*pStr1++ == *pStr2++)  
		{  
			if('\0' == *pStr1 && '\0' == *pStr2) {return 0;} //相等，返回0
		}  

		return((*(unsigned char*)pStr1 < *(unsigned char*)pStr2) ? -1 : 1);  //pSrc1大於pSrc2返回1
	}  

	return -2; //指標為空，返回-2

}

int _tmain(int argc, _TCHAR* argv[])
{
	char *pA = NULL;
	char *pB = NULL;

	std::cout << myStrCmp(NULL, "") << std::endl;
	std::cout << myStrCmp("", NULL) << std::endl;
	std::cout << myStrCmp(NULL, NULL) << std::endl;
	std::cout << myStrCmp("12", "34") << std::endl;
	std::cout << myStrCmp("34", "12") << std::endl;
	std::cout << myStrCmp("34", "14") << std::endl;
	std::cout << myStrCmp("12", "12") << std::endl;
	getchar();
	return 0;
}