Download presentation

Presentation is loading. Please wait.

Published byJace Kipps Modified over 2 years ago

1
Exercises for Chapter 2

2
Summary for the Quiz Some numbers –199 less than 100 55 Conclusion –There are students who did read textbook at least for review; –Most submitted answers are actually correct; –Rethinks on teaching method

3
Explanations on RE A regular expression defines a set of strings(language); A regular expression states the common pattern(structure) of the strings that belong to its language; For the same set of strings, there could be several RE definitions for it; Explanation of three operations –( 顺序 ; 选择 ; 重复 );

4
Example of RE {a, b, c} Defining a set of strings, where each string should starts with “a” and ends with “c”; Defining a set of strings, if “a” appears in one string, “c” should appear right after “a”;

5
From RE to NFA The generated NFA could be different, but they are equivalent; –The only criteria for judging whether the generated NFA is correct: L(RE) = L(NFA) You can follow the general rules; There are some shortcuts;

6
Rules ■ is a regular expression ， L( )={ } ■ is a regular expression ， L( )={ } ■ for any c , c is a regular expression, L(c)={c} S0S0 S S0S0 S c

7
Rules ■ ( A ), L( (A) )= L(A), no change; ■ A B ， L( A B )= L(A)L(B) NFA(A) NFA(B)

8
Rules ■ ( A ), L( (A) )= L(A), no change; ■ A | B ， L( A | B )=L(A) L(B) NFA(A) NFA(B)

9
Rules ■ A* ， L( A*)= L(A)* NFA(A)

10
Attention The rules introduced above are effective for those NFAs that have one start state and one terminal state; Any NFA can be extended to meet this requirement; …… NFA ……

11
Quiz (a|b)*abb(a|b)* Follow the rules a b a bb

12
Quiz (a|b)*abb(a|b)* Follow the process in the textbook (a|b)*abb(a|b)* (a|b)* abb (a|b)* bb b a a b a

13
Quiz (a|b)*abb(a|b)* The NFA without edge; 1 a 4 3 2 b b a b b a

14
ab {1} 0 {1,2}{1} {1,2} {1,3} {1,2}{1,4}* {1,2,4}*{1,4}* {1,2,4}* {1,3,4}* {1,2,4}*{1,4}*

15
ab {1} 0 {1,2}{1} {1,2} {1,3} {1,2}{1,4}* {1,2,4}*{1,4}* {1,2,4}* {1,3,4}* {1,2,4}*{1,4}* {1} --- S0; {1,2} --- S1; {1,3} --- S2; {1,4} --- S3; {1,2,4} --- S4; {1,3,4} --- S5; ab S0 0 S1S0 S1 S2 S1S3* S4*S3* S4* S5* S4*S3*

16
Minimizing DFA Current groups:{S0,S1,S2}, {S3,S4,S5} Splitting {S0, S1,S2} {S0,S1},{S2} Current groups:{S0,S1},{S2}, {S3,S4,S5} Splitting {S0, S1} {S0},{S1} ab S0 0 S1S0 S1 S2 S1S3*

17
Minimizing DFA Current groups:{S0},{S1},{S2}, {S3,S4,S5} Splitting {S3, S4,S5} {S3,S4,S5} ab S3*S4*S3* S4* S5* S4*S3*

18
Minimized DFA ab S0 0 S1S0 S1 S2 S1S3* S4*S3* S4* S5* S4*S3* {S0},{S1},{S2}, {S3,S4,S5} {S0} ---- 0; {S1} --- 1 ; {S2} ---- 2; {S3,S4,S5} --- 3; ab 0 1 2 3* 10 1 2 13 33

19
You should know how to do these problems!!!!

Similar presentations

OK

Regular Expressions. Notation to specify a language –Declarative –Sort of like a programming language. Fundamental in some languages like perl and applications.

Regular Expressions. Notation to specify a language –Declarative –Sort of like a programming language. Fundamental in some languages like perl and applications.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on supply chain management of nokia phone Download ppt on indus valley civilization images Ppt on ministry of corporate affairs of india Convert doc file to ppt online reader Ppt on object-oriented programming concepts polymorphism Disaster management ppt on tsunami in japan Well made play ppt on ipad Ppt on swami vivekananda thoughts Ppt on power system transients Ppt on water pollution in hindi