#include <iostream>
using namespace std;

int* Pos(int* a, int n, int& res_n) {
    int* tmp = new int[3];
    res_n = 0;
    for (int i = 0; i < 3 && i < n; ++i)
        if (a[i] > 0)
            tmp[res_n++] = a[i];
    int* res = new int[res_n];
    for (int i = 0; i < res_n; ++i) res[i] = tmp[i];
    delete[] tmp;
    return res;
}

int* last3(int* a, int n, int& res_n) {
    res_n = (n >= 3) ? 3 : n;
    int* res = new int[res_n];
    for (int i = 0; i < res_n; ++i)
        res[i] = a[n - res_n + i];
    return res;
}

int* min3(int* a, int n, int& res_n) {
    int* tmp = new int[n];
    for (int i = 0; i < n; ++i) tmp[i] = a[i];
    for (int i = 0; i < n - 1; ++i)
        for (int j = i + 1; j < n; ++j)
            if (tmp[i] > tmp[j]) { int t = tmp[i]; tmp[i] = tmp[j]; tmp[j] = t; }
    res_n = (n >= 3) ? 3 : n;
    int* res = new int[res_n];
    for (int i = 0; i < res_n; ++i) res[i] = tmp[i];
    delete[] tmp;
    return res;
}

typedef int* (*searchFunc)(int*, int, int&);

void service(int* a, int n, searchFunc f) {
    int res_n;
    int* res = f(a, n, res_n);
    cout << "Result: ";
    for (int i = 0; i < res_n; ++i) cout << res[i] << " ";
    cout << endl;
    delete[] res;
}

int main() {
    srand(time(NULL));
    int n;
    cout << "n(n>=3)= ";
    cin >> n;
    if (n < 3) {
        cerr << "Error: size Array!!";
        return 1;
    }
    int* arr = new int[n];
    for (int i = 0; i < n; ++i)
        arr[i] = rand() % 41 - 20;

    cout << "Array: ";
    for (int i = 0; i < n; ++i) cout << arr[i] << " ";
    cout << endl;

    searchFunc arrFunc[3] = { Pos, last3, min3 };

    int choice;
    do {
        cout << "\nMenu:\n"
            << "1) Array of the first 3 elements > 0\n"
            << "2) Array of the last 3 elements\n"
            << "3) Array of the 3 smallest elements\n"
            << "4) Exit\n"
            << "Select action (1-4): ";
        cin >> choice;

        if (choice >= 1 && choice <= 3)
            service(arr, n, arrFunc[choice - 1]);
        else if (choice != 4)
            cout << "Incorrect choice!\n";
    } while (choice != 4);

    delete[] arr;
    return 0;
}