18-1

void ex121()
{
    double s = 0;
    for (int i = 1; i <= 16; i++)
    {
        double x = pow(i, 3);
        if (i % 2 == 1) x = i;
        double y = i;
        if (i * i % 2 == 1) y = i * i;

        s += pow(x - y, 2);
    }
    cout << s;
}

void ex122()
{
    double s = 0;
    for (int i = 1; i <= 10; i++)
    {
        double x = i*i - i;
        if (i % 2 == 1) x = exp(i - 4);
        double y = 0;
        if (i * i % 2 == 1) y = pow(tan(i), 2);

        s += x*x - y*y;
    }
    cout << s;
}

void ex123()
{
    double p = 1;
    for (int i = 1; i <= 14; i++)
    {
        double x = i*i - i;
        if (i % 2 == 1) x = exp(i - 4);
        double y = pow(i, 4);

        p *= x*x*y*y;
    }
    cout << p;
}

void ex124()
{
    double p = 1;
    for (int i = 2; i <= 18; i++)
    {
        double x = i*i + 2;
        if (i % 2 == 1) x = pow(2, i - 4);
        double y = i*i + 2;

        p *= x*y;
    }
    cout << p;
}

void ex125()
{
    double s = 0;
    for (int i = 1; i <= 10; i++)
    {
        double x = 3;
        if (i % 3 == 0) log(i);
        double y = 3;
        if (i % 7 == 0) y = log(i) / log(3);

        s += x - y;
    }
    cout << s;
}

void ex126()
{
    double s = 0;
    for (int i = 1; i <= 16; i++)
    {
        double x = 0;
        if (i % 5 == 0) x = i;
        double y = i;
        if (i % 7 == 0) y = i * i;

        s += x - y;
    }
    cout << s;
}

void ex127()
{
    double p = 1;
    for (int i = 1; i <= 17; i++)
    {
        double x = 0;
        if (i % 2 == 1) x = pow(sin(i), 2);
        double y = 1 / tan(i);
        if (i % 2 == 1) y = tan(i);

        p *= x*x*y;
    }
    cout << p;
}

void ex128()
{
    double p = 1;
    for (int i = 1; i <= 14; i++)
    {
        double x = i*i - i;
        if (i % 2 == 0) x = exp(3*i-4);
        double y = pow(i - 1, 2);

        p *= x*y*y;
    }
    cout << p;
}

void ex129()
{
    double s = 0;
    for (int i = 1; i <= 16; i++)
    {
        double x = 1 / tan(i);
        if ((int) sqrt(i) % 1 == 0) x = tan(i);
        double y = exp(i - 4);

        s += x*y - i;
    }
    cout << s;
}

void ex130()
{
    double p = 1;
    for (int i = 1; i <= 10; i++)
    {
        double x = i*i;
        if (i % 5 == 0) x = i;
        double y = 6;
        if (i % 3 == 0) y = pow(i, 3);

        p *= x*y;
    }
    cout << p;
}