ITPEC FE Morning April 2021 Question 5
ITPEC FE Morning April 2021 — Question 5 of 80
State transition table — trace each input through the automaton to find which string reaches the failure state.
Transition table (A = initial, E = failure):
| Blank | Number | Sign | Radix | Other | |
|---|---|---|---|---|---|
| A | A | B | C | D | E |
| B | A | B | E | D | E |
| C | E | B | E | D | E |
| D | A | E | E | E | E |
Trace 12.2:
- 1 (Number): A → B
- 2 (Number): B → B
- . (Radix point): B → D
- 2 (Number): D → E ← failure
Why not others:
- (a) +0010: A → C → B → B → B → B — ends in B
- (b) −1: A → C → B — ends in B
- (d) 9.△: A → B → D → A — ends in A
Key rule: State D (after radix point) transitions to E on Number input — the automaton rejects fractional digits after a decimal point.
AI-generated — may contain errors
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