재귀 | n까지의 합

using System;
 
namespace Application
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            //n까지의 합
            int n = 10;
            //result: 55
            var sol = new Solution();
            var result = sol.solution2(n);
            Console.WriteLine("result: {0}", result);
 
        }
    }
 
    public class Solution {
        public int solution1(int n) {
            int sum = 0;
            for (int i = 0; i < n; i++) {
                sum += i;
            }
            return sum;
        }
 
        
 
        public int solution2(int n) {
            if (n == 1) return 1;
            return n + solution2(n - 1);
            
        }
    }
}