统计N（N<255）个数中正数、负数、零的个数。

条件说明：（1）N个的数据范围为16位的有符号数，存放在数据段以src为首地址的存储区域

（2）统计结果放在以dest为首地址的存储区域

2：将键盘随机输入的20个“a～z”和“A～Z”的字母，分别安大小写的顺序在屏幕上显示出来。-Statistics N (N < 255) a few number of Chiang Kai-shek, negative, and the number of zero. Conditions that: (1) N of the data range of 16-bit signed number stored in the data segment, led by a src address storage area (2) statistics on the dest in the storage area, led by Address 2: Random keyboard input 20 " a ~ z"　and " A ~ Z"　letter, an upper and lower case, respectively, the order is displayed on the screen.