#include <iostream>
#include <iomanip>
#include <random>
#include <algorithm>
#include <vector>
using namespace std;
using box_t = pair<int*, const size_t>;
class Array {
public:
    static void fill(box_t& box, const int a, const int b) {
        auto[sequence, length] = box;
        for (auto i = 0U; i < length; ++i) sequence[i] = generate(a, b);
    }
    static void show(const box_t& box, const streamsize width = 4U) {
        auto[sequence, length] = box;
        for (auto i = 0U; i < length; ++i) cout << setw(width) << sequence[i];
        cout.put('\n');
    }
    static pair<int, int> first_even(const box_t& box) {
        auto[sequence, length] = box;
        for (auto i = 0; i < int(length); ++i) if (0 == sequence[i] % 2) return { i, sequence[i] };
        return { -1, 0 };
    }
    static pair<int, int> last_pos(const box_t& box) {
        auto[sequence, length] = box;
        int pos = length - 1;
        do if (sequence[pos] > 0) break; while (--pos >= 0);
        if (pos < 0) return { -1, 0 };
        return { pos, sequence[pos] };
    }
    static void sort_increase(box_t& box, size_t start, size_t last) {
        auto[sequence, length] = box;
        if (start > last) swap(start, last);
        if (start == last || last >= length) return;
        sort(sequence + start, sequence + last);
    }
    static void show_prime(box_t& box, const streamsize width = 3U) {
        auto[sequence, length] = box;
        vector<size_t> indexes;
        for (auto i = 0; i < int(length); ++i) if (is_prime(abs(sequence[i]))) indexes.push_back(i);
        cout << indexes.size() << ';';
        for (const auto index : indexes) cout << ' ' << index;
        cout.put('\n');
    }
private:
    static int generate(int a, int b) {
        if (a > b) swap(a, b);
        const uniform_int_distribution<> uid(a, b);
        random_device rd;
        mt19937 gen(rd());
        return uid(gen);
    }
    static bool is_prime(const int num) {
        bool prime;
        if (num == 2 || num == 3 || num == 5) prime = true;
        else if (~num & 1 || num < 2 || 0 == num % 3 || 0 == num % 5) prime = false;
        else {
            int n;
            for (n = 3; n * n <= num && num % n; n += 2) { ; }
            prime = n * n > num;
        }
        return prime;
    }
};
int main() {
    const auto n = 27U;
    const auto l = -48, r = 59;
    int a[n];
    box_t box_a{ a, n };
    Array::fill(box_a, l, r);
    cout << "Array a:";
    Array::show(box_a);
    int b[n];
    box_t box_b{ b, n };
    Array::fill(box_b, l, r);
    cout << "Array b:";
    Array::show(box_b);
    auto[index_a_even, value_a_even] = Array::first_even(box_a);
    if (index_a_even != -1) cout
        << "\nThe value of the first even element for a: " << value_a_even
        << "\n The index of the first even element for a: " << index_a_even;
    auto[index_a_pos, value_a_pos] = Array::last_pos(box_a);
    if (index_a_pos != -1) cout
        << "\nThe value of the last positive element for a: " << value_a_pos
        << "\nThe index of the last positive element for a: " << index_a_pos
        << '\n';
    auto[index_b_even, value_b_even] = Array::first_even(box_b);
    if (index_b_even != -1) cout
        << "\nThe value of the first even element for b: " << value_b_even
        << "\nThe index of the first even element for b: " << index_b_even;
    auto[index_b_pos, value_b_pos] = Array::last_pos(box_b);
    if (index_b_pos != -1) cout
        << "\nThe value of the last positive element for b: " << value_b_pos
        << "\nThe index of the last positive element for b: " << index_b_pos
        << '\n';
    Array::sort_increase(box_a, index_a_even + 1, index_a_pos);
    cout << "\nArray a: ";
    Array::show(box_a);
    Array::sort_increase(box_b, index_b_even + 1, index_b_pos);
    cout << "Array b: ";
    Array::show(box_b);
    cout << "The number of prime numbers in a: ";
    Array::show_prime(box_a);
    cout << "The number of prime numbers in b: ";
    Array::show_prime(box_b);
    system("pause");
}