[C++] struct memory allocation

　　　　　　　　MAX-byte alignment (最大单位对齐)

 typedef struct user  USER;
 typedef struct employee E;
 struct user{

     char name[];  //take 12 bytes
     int age; //take 4 bytes
     short sex;//take 4 bytes
     char blood;//take 1 bytes but in  the 4 bytes of sex
 };
 struct employee{

     char name[];  //take 8 bytes
     int age; //take 4 bytes
     char blood;//take 4 bytes
 };
 int main(){

     printf("%d\n", sizeof(USER));// 12+4+4
     printf("%d\n", sizeof(E));// 8+4+4
     system("pause");
 }