UC知道regular expression的两个问题,急啊~
来源：百度知道 编辑：UC知道 时间：2024/06/05 07:24:46
regular expression
1.give a regular expression defining the set of all string over {a,b} that do not contain the substring ab.
2.give a regular expression defining the set of all strings over{a,b,c}that contain exactly two occurrences of c.
请用写这种形式的答案，谢谢了~
For example，a regular expression is constructed to represent the set of strings over{ab} that do not contain the substring aa.
Answer:b*(ab+)*∪b*(ab+)*a
1.give a regular expression defining the set of all string over {a,b} that do not contain the substring ab.
2.give a regular expression defining the set of all strings over{a,b,c}that contain exactly two occurrences of c.
请用写这种形式的答案，谢谢了~
For example，a regular expression is constructed to represent the set of strings over{ab} that do not contain the substring aa.
Answer:b*(ab+)*∪b*(ab+)*a
1.Answer:b*a*
2.Answer:(a|b)*c(a|b)*c(a|b)*
不懂
1 /[ab](?!ab)/
2 /[abc](.+?)c/
1.give正则表达式定义的所有字符串超过（甲，乙） ，但不包含子抗体。
2.give正则表达式定义的所有字符串超过（甲，乙，丙）到底包含两个发生角
正则表达式，忘了