位运算的问题,怎么判断一个数(二进制)右边起第二个数是0还是1

Question

比如说15个数,
二进制1111
怎么判断左边第一个数是1还是0
用位运算?

Answer 1

[code="java"]public class Test {
public static void main(String args[]) {
int pow = 5;

    for(byte i = 0;i < (int)Math.pow(2, pow);i ++)
    {
        //  8 is 1000, so we use (i&8) to know if the most left is 1 or 0
        if((i & (int)Math.pow(2, pow - 1)) > 0)
        {
            System.out.println("Left of Binary " + i + " is " + 1);
        }
        else
        {
            System.out.println("Left of Binary " + i + " is " + 0);
        }
    }
}

}[/code]