## What is the meaning of Dpda?

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In automata theory, a deterministic pushdown automaton (DPDA or DPA) is a variation of the pushdown automaton. The class of deterministic pushdown automata accepts the deterministic context-free languages, a proper subset of context-free languages.

### What is the difference between Dpda and Npda?

We design Finite Automata for Regular Grammar….Difference between NPDA and DPDA:

S. No | DPDA(Deterministic Pushdown Automata) | NDPA(Non-deterministic Pushdown Automata) |
---|---|---|

2. | It is possible to convert every NPDA to a corresponding DPDA. | It is not possible to convert every NPDA to a corresponding DPDA. |

#### How do you make a Dpda?

Construct a DPDA for anb2n n ≥ 1 in TOC

- PDA has three components, which is as follows −
- Step 1 − Consider input string: “aabbbb” which satisfies the given condition.
- Step 2 − Scan string from left to right.
- Step 3 − For input ‘a’ and STACK alphabet Z, then.
- Step 4 − For input ‘a’ and STACK alphabet ‘a’, then.

**What are the things to be considered in Dpda to prove the PDA is deterministic?**

A deterministic PDA is one in which there is exactly one choice of action for a given state, stack symbol and input symbol. By convention deterministic PDAs only accept by final state, but it is easy to show that is equivalent to accepting by empty stack.

**Which of the following can be accepted by a DPDA?**

Discussion Forum

Que. | Which of the following can be accepted by a DPDA? |
---|---|

b. | The set of odd length palindrome over {a,b} |

c. | {xx^c| where c stands for the complement,{0,1}} |

d. | None of the mentioned |

Answer:None of the mentioned |

## Which is more powerful Npda or DPDA?

Power of NPDA is more than DPDA. It is not possible to convert every NPDA to corresponding DPDA. Language accepted by DPDA is subset of language accepted by NPDA.

### What is a Npda?

A nondeterministic pushdown automaton (npda) is basically an nfa with a stack added to it. We start with the formal definition of an nfa, which is a 5-tuple, and add two things to it: is a finite set of symbols called the stack alphabet, and. z. is the stack start symbol.

#### What is PDA in TOC?

In the theory of computation, a branch of theoretical computer science, a pushdown automaton (PDA) is a type of automaton that employs a stack. Pushdown automata are used in theories about what can be computed by machines.

**Can DPDA accept CFL?**

A DPDA can accept languages like Lwcw that are not regular, but there are CFL (like Lwwr) that cannot be accepted by a DPDA. Theorem: If L is the language accepted by some DPDA P, then L has an unambiguous CFG. The DPDA languages are not exactly equal the subset of CFL that are not inherently ambiguous.

**Which of the following are the actions that operates on stack top?**

9. Which of the following are the actions that operates on stack top? Explanation: Push, pop and replace are all the basic and only operations that takes place on stack top.

## Why PDA is more powerful than FA?

A PDA is more powerful than FA. Any language which can be acceptable by FA can also be acceptable by PDA. PDA also accepts a class of language which even cannot be accepted by FA. Thus PDA is much more superior to FA.

### What is string in TOC?

String: String is a finite sequence of symbols from some alphabet. A string is generally denoted as w and the length of a string is denoted as |w|. Note: Σ* is a set of all possible strings(often power set(need not be unique here or we can say multiset) of string) So this implies that language is a subset of Σ*.

#### What is a DPDA?

According to the textbook’s definition, a DPDA is a PDA in which no state phas two different outgoing transitions ((p,x,α),(q,β)) and((p,x′,α′),(q′,β′)) which are compatiblein the sense that both could be applied.

**What is the difference between a DPDA and a DCFL?**

According to the textbook’s definition, a DPDA is a PDA in which no state phas two different outgoing transitions ((p,x,α),(q,β)) and((p,x′,α′),(q′,β′)) which are compatiblein the sense that both could be applied. A DCFL is basically a language which accepted by a DPDA, but we need to qualify this further.

**When does a language support a DPDA?**

When one considers whether a language Lsupports a DPDA or not, a dedicated end-of-inputsymbol is always added to strings in the language. Formally, a language Lover Σis deterministic context free, or Lis a DCFL , if

## Does the DPDA run in time or space?

since the DPDA runs in time at most c [multiplied by] n on any input of length n. To motivate this definition of [SS.sup.k], consider the diagram in Figure 1, plotting stack height versus time in a part of a computation of the DPDA. The diagram shows a stack [S.sub.1] built up by a [ [Delta].sup.k]-computation starting from .