Deterministic finite state machine
A state machine with finite states where each input leads to exactly one transition. DFAs recognize regular languages and enable lexical analysis. Determinism ensures predictable behavior.
Formula
δ(state, symbol) = next_state
Real World
A vending machine controller is a DFA: inserting a 50p coin in the 'waiting' state always transitions to exactly one 'paid' state, never ambiguously to multiple states.
Exam Focus
Check your DFA transition table has exactly one entry per state-input pair — a missing or duplicate entry loses marks.
How well did you know this?