http://blog.csdn.net/vinfcent/article/details/63310056

//****字符串转十六
int StrToHex(char *str, int num)
{
	if (*str == '0')
	{
		str+=2;
		
	}
	while(*str != '\0')
	{
		if ((*str >= '0')&&(*str <= '9'))
		{
			num = num*16 + (*str - '0');
			str++;
		}
		else if (((*str >= 'a')&&(*str <= 'f')))
		{
			num =num*16+(*str - 'a')+10;
			str++;
		}
		else if (((*str >= 'A')&&(*str <= 'F')))
		{
			num =num*16+(*str - 'A')+10;
			str++;
		}
	}
	if (*str == '-')
	{
		num = -num;
	}
	return num;
}

//*****字符串转整数
int StrToInt(char *str, int num)
{
	if (*str == '-')
	{
		str++;
	}
	while(*str != '\0')
	{
	     num = num*10 + (*str - '0');
		 str++;
	}
	if (*str == '-')
	{
		num = -num;
	}
	return num;
}


//*****整数转字符串
void IntToStr(int num,char str[])
{
	int i = 0,j=0;
	char buff[32] = {0};
	int n = num;
	if (num < 0)
	{
		num = -num;
	}
	do 
	{
		buff[i++] = num%10 +'0';
		num = num/10;

	} while (num);
	if (n < 0)
	{
		buff[i++] = '-';
	}
	buff[i] = '\0';
	
	i--;
	int cnt=i;
	for (;j <= cnt; j++)
	{
		str[j] = buff[i--];
		
	}
	str[j] = '\0';

}


//*****除法及取模实现函数,不考虑负数
int funDiv(int a,int b, bool flag)
{
	int i = 0;
	if(b == 0)//不能为0
	{
		return;
	}
		
	while(a >= b){
		a = a-b;
		i++;
	}
	if (flag)//  /
	{
		return i;
	} 
	else// %
	{
		return a;
	}
}
//******实现库函数memcpy()
void mymemcpy(void *dest,const void *src,int cnt)
{
	char *dest_t = (char*)dest;
	const char *src_t = (const char*)src;
	while(cnt--)
	{
		*dest_t = *src_t;
		dest_t++;
		src_t++;
	}
}