ЯиМП №2 вар 14

#include <vector>
#include <fstream>
#include <iostream>

using namespace std;

double multic(double* vect, int size, double b)
{
    double s = 1;
    for (int i = 0; i < size; ++i)
    {
        if(vect[i] > 0 && b <= vect[i])
            s = s * vect[i];
    }
    return s;
}

int main()
{
    ifstream fileIn;
    fileIn.open("input.txt");
    if (!fileIn)
    {
        cout << "Error: File not found" << endl;
        system("pause");
        return 0;
    }

    int size = 0;
    while (!fileIn.eof())
    {
        double a;
        fileIn >> a;
        size++;
    }
    fileIn.seekg(0, ios_base::beg); //каретка на начало
    double param;
        fileIn >> param;
        if (fileIn.fail())
        {
            cout << "Error: Incorrect value of parametr" << endl;
            system("pause");
            return 0;
        }
    double *arr = new double[size];
    int j = 0;
    while (!fileIn.eof())
    {
        double a;

        fileIn >> a;
        if (fileIn.fail())
        {
            cout << "Error: Incorrect value of element" << endl;
            system("pause");
            return 0;
        }
        arr[j] = a;
        j++;
    }
    fileIn.close();

    double result = multic(arr, size - 1, param);
    cout << "Array: ";
    for (int i = 0; i < size - 1; i++)
    {
        cout << arr[i] << ' ';
    }
    delete[] arr;
    cout << endl << "Result: " << result << endl;

    ofstream fileOut;
    fileOut.open("output.txt");
    fileOut << "Result: " << result;
    fileOut.close();

    system("pause");
    return 0;
}