A state machine is a computational model used to design algorithms and systems that can be in one of a finite number of states at any given time. It can transition from one state to another in response to external inputs or events, according to predefined rules.
State machines are used to model the behavior of systems by defining:
- States: Distinct modes or conditions that the system can be in.
- Transitions: Rules that define how the system moves from one state to another based on inputs or events.
- Events: Inputs or triggers that cause state transitions.
- Actions: Operations that may be performed during transitions or within states.
State machines can be represented using state diagrams, which visually depict the states, transitions, and events.
Example (State Machine for a Traffic Light): Consider a simple state machine for a traffic light:
- States: Red, Green, Yellow
- Transitions:
- Red to Green after a set time interval
- Green to Yellow after a set time interval
- Yellow to Red after a set time interval
A state diagram for this traffic light might look like this:
Red -> Green -> Yellow -> Red