lesson_171123

#include <iostream>

using namespace std;

//Рекурсия


int factorial(int n) {
    int res = 1;
    while (n > 1) {
        res *= n--;
    }
    return res;
}

// fact(80)
// 71569457046263802294811533723186532165
// 58465734236575257710944505822703925548
// 01488426689448672808140800000000000000
// 00000


int rec_factorial(int n) {
    if (n < 0)
        return 0;
    if (n == 1 || n == 0)
        return 1;

    cout << "before rec: " << n << endl;
    int res = n * rec_factorial(n - 1);
    cout << "after rec: " << n << endl;
    return res;
}

int fibo(int n) {
    if (n <= 1)
        return n;
    cout << n << " ";
    return fibo(n - 1) + fibo(n - 2);
}

void rec_show(int sz, int* arr) {
    if (sz == 0) {
        //cout << endl;
        return;
    }
    rec_show(sz - 1, arr);
    cout << arr[sz - 1] << " ";
}

// Алгоритм Евклида
int gcd(int a, int b) {
    if (a < 0 || b < 0)
        throw 1;
    while (true) {
        if (a == b)
            return a;
        else
            if (a > b)
                a = a % b;
            else
                b = b % a;
    }
}

// Рекурсивный алгоритм Евклида
int rec_gcd(int a, int b) {
    if (a < 0 || b < 0)
        throw 1;
    if (a == b) return a;
    if (a == 0) return b;
    if (b == 0) return a;
    if (a > b)
        rec_gcd(a % b, b);
    else
        rec_gcd(a, b % a);
}

void test_gcd() {
    if (rec_gcd(12, 12) == 12)
        cout << "GOOD" << endl;
    else
        cout << rec_gcd(12, 12) << " is not 12" << endl;

    if (rec_gcd(18, 24) == 6)
        cout << "GOOD" << endl;
    else
        cout << rec_gcd(18, 24) << " is not 6" << endl;
}

void show_chars() {
    cout << "\033[34;46m" << "Hello";
    for (int k = 0; k < 255; k++) {
        cout << k << " - " << char(k) << endl;
    }
    cout << "\033[0m";
}

int main() {
    //cout << rec_factorial(5) << endl;
    // f0 = 0, f1 = 1, 1, 2, 3, 5, 8, 13, 21...
    //cout << "res: " << fibo(7) << endl;
    //int arr[5]{ 1,2,3,4,5 };
    //rec_show(5, arr);
    //test_gcd();
    show_chars();
    return 0;
}