奇怪++操作

#include <stdio.h>

int main(void)
{
int j, i = 3;

printf("j = %d\n", j = (++i) + (++i) + (++i));

i = 3;
printf("j = %d\n", j = (i++) + (i++) + (i++));
i = 3;
printf("j = %d\n", j = (++i) + (i++) + (++i));

return 0;
}

/*
结果：
 * j = 16
* j = 9
* j = 13
* */

#include <stdio.h>

#define SQUARE(x) ((x)*(x))
int main(void)
{
int a = 5;
int b, c;

b = SQUARE(a++);
a = 5;
c = SQUARE(++a);

printf("b: %d, c: %d\n", b, c);

a = 5;
b = (a++)*(a++);
a = 5;
c = (++a)*(++a);

printf("b: %d, c: %d\n", b, c);

a = 5;
b = (a++)*(a++)*(a++);
a = 5;
c = (++a)*(++a)*(++a);

printf("b: %d, c: %d\n", b, c);

a = 5;
b = (a++)*(a++)*(++a);
a = 5;
c = (++a)*(a++)*(++a);
// 6*6*7 ?

?

?
a = 5;
c = (++a)*(a++);
// 6*6 ??

?

printf("b: %d, c: %d\n", b, c);

return 0;
}