单选题 以下程序的运行结结果是(). Plain Text#include <stdio.h>int main(){int k=1;switch(k){case 1:printf("%d",k++);case 2:printf("%d",k++);case 3:printf("%d",k++);case 4:printf("%d",k+ +);break;default:printf("ful!!\n");}return 0;}