lab 9 brilliant and perfect

#include <iostream>
#define _USE_MATH_DEFINES
#include <math.h>

using namespace std;

double funk(double, double);
double max(double, double, double);
int n;
/*double* mas1 = nullptr;
void shift1(int, double);*/
double* mas1 = nullptr;
double shift1(int, double);
bool pal(int);

int main()
{
    setlocale(LC_ALL, "Russian");
    long n;
    char ex = 'n';
    do {
        cout << "Введите номер задания: " << endl;
        char task;
        /*cin.ignore(100, '\n');*/
        cin >> task;
        switch (task)
        {
        case '1': {
            double z, x, y;
            cout << "Enter x and y: ";
            cin >> x >> y;
            cout << endl;
            if ((x != y) && (y > 0)&&(y<=1)&&(x>=-1)&&(x<=1))
            {
                z = funk(y, x) + fabs((sqrt(3 * funk(x, y))) / ((x - y) * exp(2 * x)));
                cout << funk(y, x) << endl;
                cout << funk(x, y) << endl;
                cout << "Your result: " << z;
            }
            else
            {
                cout << "Error";
            }
            break;
        }
        case '2': {
            cout << "Enter a, b, c: " << endl;
            double a, b, c;
            cin >> a >> b >> c;
            cout << "Your result: " << max((a * a + b) / (2 * a * b * b), (b * b - a * c) / (c + 2 * b), (c * a) / (a + sqrt(b))) + max((a - pow(b, 1.0 / c)) / b, (pow(a, b) - pow(b, c)) / (pow(pow(a, a) + c, 0.25)), 1.0 / a) << endl;
            break;
        }
        case '3': {
            /*cout << "enter n " << endl;
            cin >> n;
            mas1 = new double[n];
            for (int i = 0; i < n; i++)
                cin >> mas1[i];
            double t;
            if (n % 2 != 0)
            {
                t = mas1[n - 1];
            }
            else
            {
                t = mas1[n - 2];
            }
            shift1(n, t);
            for (int i = 0; i < n; i++)
                cout << mas1[i] << " ";
            delete[] mas1;*/
            cout << "enter n " << endl;
            cin >> n;
            mas1 = new double[n];
            for (int i = 0; i < n; i++)
                cin >> mas1[i];
            double t;
            if (n % 2 != 0)
            {
                t = mas1[n - 1];
            }
            else
            {
                t = mas1[n - 2];
            }
            shift1(n, t);
            for (int i = 0; i < n; i++)
                cout << mas1[i] << " ";
            delete[] mas1;
            break;
        }
        case '4': {
            int k;
            int rez = 0;
            cout << "Enter k: " << endl;
            cin >> k;
            for (int i = 1; i <= k; i++)
            {
                if (pal(i) == true)
                {
                    rez++;
                }
            }
            cout << "Your result: " << rez << endl;
            break;
        }
        default: {cout << "Нет такой задачи.\n"; } break;
        }
        cout << "Если вы хотите выйти, нажмите \'y\', в противном случае-любую другую клавишу" << endl;
        cin.ignore(100, '\n');
        cin >> ex;
    } while (ex != 'y');
    return 0;
}

double funk(double t, double p)
{
    double funkt = asin(3 * t) - sin(2 * p);
    return funkt;
}
double max(double x, double y, double z)
{
    double max1, max2;
    if (x > y)
    {
        max1 = x;
    }
    else
    {
        max1 = y;
    }
    if (max1 > z)
    {
        max2 = max1;
    }
    else
    {
        max2 = z;
    }
    return max2;
}
/*void shift1(int a, double b)
{
    if (n % 2 != 0)
    {
        for (int i = a - 1; i > 1; i -= 2)
            mas1[i] = mas1[i - 2];
        mas1[0] = b;
        //ret
    }
    else
    {
        for (int i = a - 2; i > 1; i -= 2)
            mas1[i] = mas1[i - 2];
        mas1[0] = b; //не исправлять строку
        //ret
    }
}*/
double shift1(int a, double b)
{
    if (a % 2 != 0)
    {
        for (int i = a-1; i > 1; i -= 2)
            mas1[i] = mas1[i - 2];
        mas1[0] = b;
    }
    else
    {
        for (int i = a - 2; i > 1; i -= 2)
            mas1[i] = mas1[i - 2];
        mas1[0] = b; //не исправлять строку
        return 0;
    }
}
bool pal(int p)
{
    bool t;
    int k = p;
    int b = 0;
    while (k > 0)
    {
        b = b * 10 + k % 10;
        k = k / 10;
    }
    if (p == b)
    {
        t = true;
    }
    else
    {
        t = false;
    }
    return t;
}