1. Models of Computation

2. Outline of the course contents
Computation
memory
CPU

3. temporary memory
input
CPU
output
Program memory

4. Example: temporary memory input CPU output Program memory compute

5. temporary memory
input
CPU
output
Program memory
compute
compute

6. temporary memory
input
CPU
output
Program memory
compute
compute

7. temporary memory
input
CPU
Program memory
output
compute
compute

8. Automaton
temporary memory
Automaton
input
CPU
output
Program memory

9. Automaton
temporary memory
Automaton
input
output
transition
state

10. Different Kinds of Automata
Automata are distinguished by the temporary memory
Finite Automata: no temporary memory
Pushdown Automata: stack
Turing Machines: random access memory

11. Finite Automaton temporary memory input Finite Automaton output
Example: Elevators, Vending Machines
(small computing power)

12. Pushdown Automaton Stack Push, Pop input Pushdown Automaton output
Temp.
memory
Stack
Push, Pop
input
Pushdown
Automaton
output
Example: Compilers for Programming Languages
(medium computing power)

13. Turing Machine Random Access Memory input Turing Machine output
Temp.
memory
Random Access Memory
input
Turing
Machine
output
Examples: Any Algorithm
(highest computing power)

14. Power of Automata Finite Automata Pushdown Automata Turing Machine
Simple
problems
More complex
problems
Hardest
problems
Finite
Automata
Pushdown
Automata
Turing
Machine
Less power
More power
Solve more
computational problems

15. Turing Machine is the most powerful
computational model known
Question: Are there computational
problems that a Turing Machine
cannot solve?
Answer: Yes
(unsolvable problems)

16. Time Complexity of Computational Problems:
NP-complete problems
Believed to take exponential
time to be solved
P problems
Solved in polynomial time

17. This Summary is an Online Content from this Book: Michael Sipser, Introduction to the Theory of Computation, 2ndEdition It is edited for Computation Theory Course by: T.Mariah Sami Khayat Teacher Adam University College For Contacting:
Kingdom of Saudi Arabia
Ministry of Education
Umm AlQura University
Adam University College
Computer Science Department
المملكة العربية السعودية
وزارة التعليم
جامعة أم القرى
الكلية الجامعية أضم
قسم الحاسب الآلي