说明：   该序列存储在一组连续的空间(数组)中，各个元素之间具有先后关系，按照此关系各个元素呈现出一条线状的序列，如a1,a2,a3,…,an-1, an。  该序列中除第一个元素（称首元素）外，每个元素有且仅有一个直接前驱元素；  除最后一个元素（称尾元素）外，每个元素有且仅有一个直接后继元素。
( The sequence is stored in a group of contiguous space (an array), the various elements of the relationship between the successively, in accordance with the various elements of this relationship has shown a linear sequence, such as a1, a2, a3, ..., an-1, an .  The sequence, in addition to the first element (called the first elements), each element has one and only one element of the direct precursor  In addition to the last element (called the end of elements), each element has one and only one element of the direct successor .)