c++ vector getMax(vector operations) { vector result; stack stk; stack maxStack;

for (string op : operations) {
    stringstream ss(op);
    int command, value;
    ss >> command;

    if (command == 1) {
        ss >> value;
        stk.push(value);
        if (maxStack.empty() || value >= maxStack.top()) {
            maxStack.push(value);
        }
    } else if (command == 2) {
        if (!stk.empty()) {
            if (stk.top() == maxStack.top()) {
                maxStack.pop();
            }
            stk.pop();
        }
    } else if (command == 3) {
        if (!maxStack.empty()) {
            result.push_back(maxStack.top());
        }
    }
}

return result;

}