#include <iostream>
using namespace std;

void Pos(int* a, int n) {
    int count = 0;
    for (int i = 0; i < 3 && i < n; ++i)
        if (a[i] > 0) ++count;
    cout << "The number of the first 3 elements > 0: " << count << endl;
}

void Show1(int* a, int n) {
    cout << "The last 3 elements: ";
    for (int i = (n >= 3 ? n - 3 : 0); i < n; ++i)
        cout << a[i] << " ";
    cout << endl;
}

void Show2(int* a, int n) {
    int* b = new int[n];
    for (int i = 0; i < n; ++i) b[i] = a[i];

    for (int i = 0; i < n-1; ++i)
        for (int j = i+1; j < n; ++j)
            if (b[i] > b[j]) { int t = b[i]; b[i] = b[j]; b[j] = t; }
    cout << "The three smallest elements: ";
    for (int i = 0; i < 3 && i < n; ++i) cout << b[i] << " ";
    cout << endl;
    delete[] b;
}

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

void service(int* a, int n, searchFunc f) {
    f(a, n);
}

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, Show1, Show2 };

    cout << "Menu:\n"
         << "1) The number of the first 3 elements > 0\n"
         << "2) Show the last 3 items\n"
         << "3) Display the 3 smallest elements\n"
         << "Select an action (1-3): ";
    int choice;
    cin >> choice;
    if (choice >= 1 && choice <= 3)
        service(arr, n, arrFunc[choice-1]);
    else
        cout << "Incorrect choice!\n";

    delete[] arr;
    return 0;
}