ITPEC FE Morning April 2022 Question 5
ITPEC FE Morning April 2022 — Question 5 of 80
State Transition Table — trace each input string through the automaton to find which is rejected (reaches state E).
Table rules (start at state A, reject on E):
- State A: Blank→A, Number→B, Sign→C, Radix point→D, Other→E
- State B: Blank→A, Number→B, Sign→E, Radix point→D, Other→E
- State C: Blank→E, Number→B, Sign→E, Radix point→E, Other→E
- State D: Blank→A, Number→E, Sign→E, Radix point→E, Other→E
Tracing each option:
- •(a) +0010: A→C→B→B→B→B → accepted
- •(b) −1: A→C→B → accepted
- •(c) 12.2: A→B→B→D→E → rejected
- •(d) 9.△: A→B→D→A → accepted
Why (c) is rejected:
- After the radix point, the automaton is in state D
- State D + Number → E (error state)
Key rule: In this automaton, a digit after a radix point is invalid — state D does not accept numbers.
AI-generated — may contain errors
The original exam layout is preserved in the image so diagrams, formulas, tables, and code remain accurate.
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