编程首三行(程序第一行代码的作用) 1、int val34=1,2,3,4,5,6,7,8,9,10,11,12,num,i=0fori=0ilt4i++ num=val2ival2i=val0ival0i=num;include ltstdiohint main int i = 0, j = 0 int a33 = 0 int...