Formal Languages Questions
The main difference between a deterministic finite automaton (DFA) and a pushdown automaton (PDA) lies in their computational power and the memory they possess.
A DFA is a type of automaton that recognizes regular languages. It has a finite number of states and reads input symbols one at a time, transitioning between states based on the current state and the input symbol. DFAs do not have any memory or stack to store information about previous inputs.
On the other hand, a pushdown automaton (PDA) is more powerful and can recognize context-free languages. It has a stack, which allows it to store and retrieve information during its computation. PDAs can read input symbols, change states, and manipulate the stack based on the current state, input symbol, and top of the stack.
In summary, the key difference is that a DFA is a simpler automaton that recognizes regular languages and lacks memory, while a PDA is more complex, recognizes context-free languages, and possesses a stack for memory storage.