求数组逆序的函数。从键盘输入int型数组a[ 20 ]的20 个元素值，函数实现对数组元素数据的逆序放置。即第1个元素与第20个元素互换，第2个元素与第19个元素互换，……，第10个元素与第11个元素互换。压缩包内共两种方法。-Find an array reverse function. Input from a keyboard int array [20] of the 20 elements of the value placed on the reverse function to achieve an array element data. Ie an element of the first 20 elements interchangeable, the first two elements of the first 19 elements interchangeable, ......, the first 10 elements of the first 11 elements are interchangeable. Compressed package of two ways.