public static void main(String[] args){
Scanner input = new Scanner (System.in);
int tem;
System.out.println("输入正整数a: ");
tem=input.nextInt();
System.out.println("a的二进制表示为: "+Integer.toBinaryString(tem));
System.out.println("a<<2 ="+(tem<<2)+"("+Integer.toBinaryString(tem<<2)+")");
System.out.println("a>>2 ="+(tem>>2)+"("+Integer.toBinaryString(tem>>2)+")");
}