运行下面,若从键盘输入数据为"123",则输出结果是( ) #include "stdio.h" void 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); } }