3 Question about RegEx，DFA

Suppose you were modifying the Java compiler to include a new encryptedd keyword that causes Java to store the contents of the specified variable in encrypted form. E.g. encrypted String password = “hello”; would cause the contents of password to be encrypted. Which of the phases of the Java compiler would need to be modified and why? 2. For each of the following languages give the regular expression that matches the strings in the language. Note: You can use . to denote “any” character in the alphabet. (a) [5 marks] The language over the English alphabet of strings that begin and end with vowels (assume ’y’ is a vowel). (b) [5 marks] The language of strings over alphabet Σ = {xyz} whose length is divisible by 5. E.g. xyzyx. (c) [5 marks] The language over the alphabet of decimal digits of strings that represent integers divisible by 200. E.g. 13400. (d) [5 marks] The language of strings over the alphabet Σ = {abc} that do not contain the substring ac. E.g. abcab. 3. For each of the following languages give a DFA (graphical representation) that recognizes the language. (a) [5 marks] The language of all strings over the alphabet Σ = {xyz} that end in either xx or yy. E.g. xyzyxzxx. (b) [5 marks] The language of words over the alphabet Σ = {a} whose length is not divisible by 4. E.g. aaa. (c) [5 marks] The language of trinary strings (Σ = {012}) such that the sum of the digits is divisible by 3. E.g. 012102. please dont copy answers from Cheggthx. Requirements: explanation