编译原理与实践第二章答案
The exercises of Chapter Two2.1 Write regular expression for the following character sets, or give reasons why no regular expression can be written:
a. All strings of lowercase letters that begin and end in a.
a*a | a
b. All strings of lowercase letters that either begin or end in a ( or both)both: a(a|b|c|„|z)* a
**** Hidden Message *****
页:
[1]