给定一个数组，判断其中的数据序列是否左右对称：偶数个数时，左右两半部分正好逆序；奇数时，除中间位置数外，左右逆序。(学堂在线课后作业)-Given an array, which determines whether a data sequence symmetrical: an even number when the two halves of just the reverse　an odd number, in addition to the number of intermediate positions, the left and right in reverse order. (School Online Homework)