题目：输入16位整数x，如0x1234，将其转为Big Endian格式再输出，此例为输出 0x3412
来源：某500强企业面试题目
思路：将x左移8位得到a，将x右移8位得到b，a+b即为所得
//----------------------------------------
// 写一个宏，将16位的整数转为Big Endian
//----------------------------------------
#define ConvertToBigEndian(x) (((x)<<8) & 0xFF00) +(((x)>>8) & 0x00FF)
void TestConvertToBigEndian(void) {
short a = 0;
short b = 0;
// 下面输出为：ConvertToBigEndian(0x1234) = 0x3412
a = 0x1234;
b = ConvertToBigEndian(a);
printf("ConvertToBigEndian(0x%04X) = 0x%04X\n", a, b);
// 下面输出为：ConvertToBigEndian(0x12) = 0x1200
a = 0x12;
b = ConvertToBigEndian(a);
printf("ConvertToBigEndian(0x%04X) = 0x%04X\n", a, b);
}