试题C数列求值

problemJB05.png

代码实现

    public static int getResult(int index){
         int a = 1, b = 1, c = 1;
         // 要是求第四项，则i < 4, 同理推得求20190324，则i < 20190324。
         for (int i = 3; i < index; i++) {
              int sum = (a + b + c)%100000;
              a = b;
              b = c;
              c = sum;
             }
         return c;
    }