将存放数字的list，顺序排列，然后，判断，数字是否是连续的

/**
 * Created by 小蜗牛 on 2018/9/7.
 */
public class LambdaTest {
    public static void main(String[] args) {
        List list = Arrays.asList(5,2,3,1,9);
        int N = list.size();
        int t = 0;
        Collections.sort(list);
        System.out.println(list);
        boolean flag = true;
        for(int i=0; i<list.size()-1 ; i++){
            int a = (int)list.get(i+1);
            int b = (int)list.get(i);
            int c = a - b;
            if(c != 1){
                flag = false;
                System.out.print("期数不连续，请选择连续期数");
                break;
            }
        }
        System.out.println(flag);
    }
}