Programming Languages

Sample Final Exam

Question $1$

Give a regular expression for each of the following languages over $=\{0,1,...,9\}.$

$1.$ All $5-$digit integers that contain no leading zeros.

$2.$ All positive integers that begin with $9$ and that are multiples of $5.$

$3.$ All strings that begin with $9$ and contain three consecutive $1$s$.$

Question $2$

Give a DFA for each of the languages in Question $1.$