程序接收用户键入的一行字符（字符个数不超过80个，该字符用回车符结束），并按字母、数字、及其他字符分类计数，然后将结果存入以letter，digit，other为名的存取单元中-Program receives the user to type a line character (number not more than 80 characters, the characters end with a carriage return),