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Parsing A Boolean Expression

A boolean expression is an expression that evaluates to either true or false.

A boolean expression is an expression that evaluates to either true or false. It can be in one of the following shapes:

Given a string expression that represents a boolean expression, return the evaluation of that expression.

It is guaranteed that the given expression is valid and follows the given rules.

Parsing A Boolean Expression diagram

Example 1

Input: expression = "&(|(f))"

Output: false

Explanation: First, evaluate |(f) --> f. The expression is now "&(f)". Then, evaluate &(f) --> f. The expression is now "f". Finally, return false.

Example 2

Input: expression = "|(f,f,f,t)"

Output: true

Explanation: The evaluation of (false OR false OR false OR true) is true.

Example 3

Input: expression = "!(&(f,t))"

Output: true

Explanation: First, evaluate &(f,t) --> (false AND true) --> false --> f. The expression is now "!(f)". Then, evaluate !(f) --> NOT false --> true. We return true.

Constraints

  • 1 <= expression.length <= 2 * 10^4
  • expression[i] is one following characters: '(', ')', '&', '|', '!', 't', 'f', and ','.

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