MCS  265: Theory of Computation
Spring 2005

Homework problems   Reading assignments
MCS-265 homepage
Homework guidelines Course Summary
Prof. Barbara Kaiser

All Homework Assignments

Due 5/13
Practice problems:
  • Chapter 7, #7.1, 7.2, 7.6, 7.7, 7.12
Hand in:
Due 4/22
Practice problems:
  • Chapter 5, #5.4, 5.5.,5.6, 5.7
Hand in:
  • Sipser, problems  5.9, 5.12, 5.21
  • Show that the language consisting of all Turing machines which accept all palindromes is undecidable.  Use a reduction argument. 
Due 4/14
Practice problems:
  • Chapter 4: #4.2, 4.3, 4.6, 4.7, 4.8
Hand in:
  • Sipser, problems 2.14, 2.19, 4.10, 4.21  (For problem 2.19, think about parse trees.)
  • In class on 4/56 we definded a relation on the set of states of a DFA. Prove this relation is an equivalence relation.
  • Find  a minimal DFA for the DFA given in class on 4/7.
Due 3/24
Practice problems:
  • Chapter 3: #3.1, 3.2,3.5, 3.15
Hand in:
  • Sipser, problems 3.8a, 3.8b, 3.8c, 3.11, 3.14
Due 3/7
Practice problems:
  • Chapter 2, 2.3, 2.6, 2.7, 2.8
Hand in:
  • Sipser, problems 2.15, 2.16, 2.17 and 2.18a
  • Find a context-free grammar for the language (over {a,b}) A ={ all strings that have twice as many a's as b's}.
  • Find a pushdown automaton for the language in the previous problem.
Due 2/28
Practice problems:
  • Section 1.3, 1.6a, 1.7a,1.15, 1.16
  • Section 1.4, 1.17, 1.18
Hand in:
  • Using problem 1.10 in Sipser show that the intersection of two regular languages is also regular.
  • Do problem 1.41 in Sipser
  • Suppose x is a string in Sigma*.  Show that the set of all strings which have x as a prefix is a regular language.  Then show that if A is a regular language, the set of all strings in A which do not have x as a prefix is also a regular language.
  • Show that the language P = {1^n such that n is a (non-negative, integer) power of 2} is not regular.
  • Do problem  1.37 in Sipser.  Be sure to  show both things, that F satisfies the pumping lemma and that it is not regular.
Due 2/17
Practice problems:
  • Chapter 0, 1 - 8
  • Section 1.1, 1.1-1.4
  • Section 1.2, 1.4 - 1.5, 1.7a, 1.8a, 1.12
Hand in:
  • Chapter 1, 1.4d
  • 1.4i.  Give both a finite state diagram and a formal description of the DFA
  • Construct a DFA that accepts the set of strings (over 0,1) which have at leaxt three consecutive 0's in them.
  • 1.10, 1.24, 1.29




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