Question
Official answer and solution
- Official answer
- A
- From
- Official GATE 2014 answer key
Solution
Trace the execution of the NFA for the input string '0011' step by step, tracking the set of reachable states.
The initial state is .
-
Input symbol '0':
- From , on '0' there is only a self-loop back to .
- Set of reachable states: .
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Input symbol '0':
- From , on '0' self-loop stays at .
- Set of reachable states: .
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Input symbol '1':
- From , on '1' the automaton can take the self-loop back to , or take the transition to .
- Set of reachable states: .
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Input symbol '1':
- From , on '1' can go to (self-loop) or (transition).
- From , on '1' transitions to .
- Union of reachable states: .
Note that is not reachable because reaching from requires an input transition after being in .
Thus, the set of reachable states is .
A
Assuming the transition from to occurs immediately on the same symbol that reached .
The answer is the one in the official GATE answer key. The solution is this site's own explanation.
Source
- Paper
- GATE 2014 Computer Science and Information Technology (CS) Session 1
- Question
- 26 of 65, printed as CS Q.16
- Section
- Computer Science and Information Technology
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