void plusMinus(vector<int> arr) {
    size_t nPositive = 0;
    size_t nNegative = 0;
    size_t nZero = 0;
    
    for(int val : arr){
        if(val > 0){
            nPositive += 1;
        }
        else if(val < 0){
            nNegative += 1;
        }
        else{
            nZero += 1;
        }
    }
    
    double fracPositive = nPositive/static_cast<double>(arr.size());
    double fracNegative = nNegative/static_cast<double>(arr.size());
    double fracZero = nZero/static_cast<double>(arr.size());
    
    std::cout << std::fixed;
    std::cout << std::setprecision(6);
    std::cout << fracPositive << std::endl;
    std::cout << fracNegative << std::endl;
    std::cout << fracZero << std::endl;
}