求 0—7 所能组成的奇数个数

package cskaoyan;
 
public class cskaoyan43 {
    @org.junit.Test
    public void odd() {
        long sum = 4;
        long s = 4;
        long i = 0;
 
        for (i = 2; i <= 8; i++) {
            System.out.println((i - 1) + "位数为奇数的个数" + s);
 
            if (i <= 2) {
                s *= 7;
            } else {
                s *= 8;
            }
 
            sum += s;
        }
 
        System.out.println((i - 1) + "位数为奇数的个数" + s);
        System.out.println("奇数的总个数为：" + sum);
    }
}