从键盘输入10个有符号十进制数，存放到数组array中。可实现以下功能：

1.求出10个有符号数的平均值存入到wmed存储单元中并输出。

2.在存储空间中将十个有符号数进行降序存储，完成后输出。

3.统计十个有符号数中的正负数的个数并输出。

-Enter the 10 signed decimal numbers　the keyboard, stored in an array of array. Enables the following features: 1. 10 have calculated the mean number of symbols stored in the storage unit and wmed output. 2. in the storage space of ten signed descending store, after the completion of the output. 3. Statistics of ten the number of positive and negative numbers, and symbols in the output.