以下程序的功能是根据输入的“y”(“Y”)与“n”(“N”)，在屏幕上分别显示出“ThisisYES.”与“ThisisNO.”。请填空。voidYesNo(charch){switch(ch){case‘y’:case‘Y’:printf(“\nThisisYES.\n”);_________;case‘n’:case‘N’:printf(“\nThisisNo.\n”);}}intmain(){charch;printf(“Enterachar‘y’,‘Y’or‘n’,‘N’:”);ch=____________;printf(“ch:%c”,ch);YesNo(ch);}