小编use*_*371的帖子

/*
 * ezThreeFourths - multiplies by 3/4 rounding toward 0,
 *   Should exactly duplicate effect of C expression (x*3/4),
 *   including overflow behavior.
 *   Examples: ezThreeFourths(11) = 8
 *             ezThreeFourths(-9) = -6
 *             ezThreeFourths(1073741824) = -268435456 (overflow)
 *   Legal ops: ! ~ & ^ | + << >>
 *   Max ops: 12
 *   Rating: 3
 */

int ezThreeFourths(int x) {
   int z = x+x+x;
   int sign_z = z>>31;
   return ((z>>2)&(~sign_z)) + (((z>>2)+1)&sign_z);
}

我试图解决这个难题但是

ERROR: Test ezThreeFourths(-2147483648[0x80000000]) failed...
...Gives -536870911[0xe0000001]. …