What is the regular expressions for 1- String with rxactly 3 0s : 2- String at...
Give regular expressions generating the languages of 1. {w over the alphabet of {0, 1} | w is any string except 11 and 111} 2. {w over the alphabet of {0, 1} | w contains at least two 0’s and at most one 1} 3. {w over the alphabet of {0, 1} | the length of w is at most 9} 4. {w over the alphabet of {0, 1} | w contains at least three 1 s} 5. {w over...
This question deals with NFAs, DFAs, and regular expressions. (a) Using only the symbols described in the lecture slides, write a regular expression that describes all strings over the alphabet Σ = {0,1} that are at are at least four bits long and begin and end with the same bit. (b) Draw a DFA, that accepts strings strings over the alphabet Σ = {0, 1} such that if you read the string from left to right, the difference between the...
Write down the regular expressions for the following set of strings over {a, b}: 1.Strings that contain no more than one occurrence of the string aa. 2.All strings containing aba: 3.All strings of odd length 4.A string in this language must have at least two a's. 5.All strings that begin with a, and have an even number of b Bonus - All strings with “a” at every odd position
How many binary sequences of length 20 are there that(a) Start with a run of 0s—that is, a consecutive sequence of (at least) one 0—then a run of 1s, then a run of 0s, then a run of 1s, and finally finish with a run of 0s?(b) Repeat part (a) with the constraint that each run is of length at least 2.
Question 1 - Regular Expressions Find regular expressions that define the following languages: 1. All even-length strings over the alphabet {a,b}. 2. All strings over the alphabet {a,b} with odd numbers of a's. 3. All strings over the alphabet {a,b} with even numbers of b’s. 4. All strings over the alphabet {a,b} that start and end with different symbols. 5. All strings over the alphabet {a, b} that do not contain the substring aab and end with bb.
Discrete mathematics 2) Let be eumber of ternary strings (of 0s, 1s and 2s) of length n that have no adjacent even digits. For example, so (the empty string), s3 (the strings 0, 1 and 2), while s2 5: 01, 0, 12, 2 because the strings 00,02, 20, 22 are not allowed, as they have adjacent even digits. As another example, the string 10112 is allowed, while the strings 10012 and 120121 are not allowed (a) Find #3; (b) find...
Regular expressions, DFA, NFA, grammars, languages Regular Languages 4 4 1. Write English descriptions for the languages generated by the following regular expressions: (a) (01... 9|A|B|C|D|E|F)+(2X) (b) (ab)*(a|ble) 2. Write regular expressions for each of the following. (a) All strings of lowercase letters that begin and end in a. (b) All strings of digits that contain no leading zeros. (c) All strings of digits that represent even numbers. (d) Strings over the alphabet {a,b,c} with an even number of a's....
Give English descriptions of the languages represented by the following regular expressions. The descriptions should be simple, similar to how we have been defining languages in class(e.g., “languages of binary strings containing 0 in even positions. . .”). Note: While describing your language, you don’t want to simply spell out the conditions in your regular expressions. E.g., if the regular expression is 0(0 + 1)∗, an answer of the sort “language of all binary strings that start with a 0”...
Give the regular expressions of the following languages (alphabet is ab): a. {w | w has a length of at least three and its second symbol is a b} b. {w | w begins with an a and ends with a b} c. {w | w contains a single b} d. {w | w contains at least three a's} e. {w | w contains the substring baba} d. {w | w is a string of even length} e. The empty...
1. Write regular expressions to capture the following regular languages: (a) The set of binary strings which have a 1 in every even position. (Note: odd positions may be either 0 or 1.) (b) The set of binary strings that do not contain 011 as a substring. (c) Comments in Pascal. These are delimited by (* and *) or by { and }, and can contain anything in between; they are NOT allowed to nest, however. 2. Write a DFA...