Syntax error Explain the balancing parenthesis of PDA

Explain the balancing parenthesis of PDA

Pushdown Automata (PDA) are the finite automata (FAs), but with the ability to push and pop symbols to/from a stack.

PDA accepts strings if there is a legal path from start state to acceptance state for input. Otherwise, the string is rejected.

A PDA can be represented by a 7-tuple

(Q, ∑, ?, q0, ha, ?,δ)

Where

The PDA is to finite subsets of Q ? (? ∪ {?})*.

Parentheses are balanced if

  • While reading string, number of opening parentheses >= number of closing parentheses.
  • When string is read, number of opening parentheses = number of closing parentheses.

Examples

  • (())() − Balanced
  • ((()() − Not balanced
  • )()(() − Not balanced

The context free grammar (CFG) is as follows −

S -> (S) | SS | ε

PDA for balancing brackets

Each (is pushed, each) causes an (to be popped). This is shown below

Updated on: 2021-06-16T13:04:29+05:30

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