Recursion

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Recursion
{
    class Program
    {
        static long Factorial(long n)
        {
            if (n == 0)
            {
                return 1; // дъно
            }
            return Factorial(n - 1) * n;
        }

        static void OneToN(int n)
        {
            if (n == 0)
            {
                return; // дъно
            }
            OneToN(n - 1);
            Console.WriteLine(n);
        }

        static void NToOne(int n)
        {
            if (n == 0)
            {
                return; // дъно
            }
            Console.WriteLine(n);
            OneToN(n - 1);
        }

        static void Triangle(int n)
        {
            if (n == 0)
            {
                return;
            }
            Console.WriteLine(new string('*', n));
            Triangle(n - 1);
            Console.WriteLine(new string('*', n));
        }

        static int Fib(int n)
        {
            if (n == 1 || n == 2)
            {
                return 1;
            }
            return Fib(n - 2) + Fib(n - 1);
        }

        static double Power(double a, int n)
        {
            if (n == 0)
            {
                return 1;
            }
            if (n < 0)
            {
                return 1 / Power(a, -n);
            }
            return Power(a, n - 1) * a;
        }
        static void Main(string[] args)
        {
            Console.WriteLine(Power(2, 0));
            Console.WriteLine(Fib(6));
            Triangle(10);
            //OneToN(10);
           // Console.WriteLine(Factorial(5)); // 1 * 2 * 3 * 4 * 5 = 120
           // Console.WriteLine(Factorial(6));  // 720
        }
    }
}