Java位运算 左移1位相当于乘2
2的n次方计算
http://www.nowcoder.com/questionTerminal/35a1e8b18658411388bc1672439de1d9
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); while (sc.hasNext()) { System.out.println(1 << sc.nextInt()); } } }