public static String isBalanced(String s) {
        Stack<Character> stack = new Stack<>();

        for (char c : s.toCharArray()) {
            if (c == '(' || c == '{' || c == '[') {
                stack.push(c);
            } else {
                if (stack.isEmpty()) {
                    return "NO";
                }
                char top = stack.pop(); 
                if ((c == ')' && top != '(') || (c == '}' && top != '{') || (c == ']' && top != '[')) {
                    return "NO";
                }
            }
        }
        return stack.isEmpty() ? "YES" : "NO";
    }