运行下面,若从键盘输入数据为 "123" ,则输出结果是 ( ) 。 int main( ) { int num, i, j, k, place; scanf("%d", &num); if (num > 99) place = 3; else if(num > 9) place = 2; else place = 1; i = num / 100; j = (num – i * 100) / 10; k=(num - I * 100 - j * 10); switch (place) { case 3: printf("%d%d%d\n", k, j, i); break; case 2: printf("%d%d\n", k, j); break; case 1: printf("%d\n", k); } }