void DoesSomething(int *first, int *second)
{
*first = *second - *first;
*second = *second - *first;
*first = *second + *first;
}
就是first和second互相交換
void DoesSomething(int *first, int *second)
{
int tmp = *first;
*first = *second;
*second = tmp;
}