solution.java

import java.util.*;

class Solution {
    public boolean parseBoolExpr(String expression) {
        Stack<Character> stack = new Stack<>();

        for (char c : expression.toCharArray()) {
            if (c == ')') {
                List<Character> subExpr = new ArrayList<>();
                while (stack.peek() != '(') {
                    subExpr.add(stack.pop());
                }
                stack.pop(); // Remove '('

                char op = stack.pop(); // Get the operator

                if (op == '!') {
                    stack.push(subExpr.get(0) == 't' ? 'f' : 't');
                } else if (op == '&') {
                    char result = 't';
                    for (char e : subExpr) {
                        if (e == 'f') {
                            result = 'f';
                            break;
                        }
                    }
                    stack.push(result);
                } else if (op == '|') {
                    char result = 'f';
                    for (char e : subExpr) {
                        if (e == 't') {
                            result = 't';
                            break;
                        }
                    }
                    stack.push(result);
                }
            } else if (c != ',') {
                stack.push(c);
            }
        }

        return stack.peek() == 't';
    }
}