Input: expression ="&(|(f))"Output: falseExplanation:
First, evaluate |(f)--> f. The expression is now "&(f)".Then, evaluate &(f)--> f. The expression is now "f".Finally,returnfalse.
Input: expression ="!(&(f,t))"Output: trueExplanation:
First, evaluate &(f,t)-->(false AND true)-->false--> f. The expression is now "!(f)".Then, evaluate !(f)--> NOT false-->true. We returntrue.
We can evaluate the Boolean expression using a stack-based approach. Here is a step-by-step description:
Stack Usage: Use a stack to keep track of characters and sub-expressions as we parse through the input string.
Character Handling:
Operands: Push t and f onto the stack.
Operators and Parentheses: When encountering &, |, and !, push them onto the stack.
Closing Parenthesis ): Start evaluating the expression when encountering ). Pop elements from the stack until a matching ( is found. Depending on the operator, compute the result for the sub-expression and push the result back onto the stack.
Evaluation of Sub-Expressions:
NOT !: Negate the sub-expression.
AND &: Evaluate the AND operation over multiple sub-expressions.
OR |: Evaluate the OR operation over multiple sub-expressions.
Final Result: The final result of the evaluation will be left at the top of the stack once the entire expression is processed.