唉，数学不好，求助年递增率问题

Question

项目需求
1)金额10000元 ，每3年固定递增5%，共计算18年
2）金额10000元 ，每3年递增5%，接着3年递增7% 接着递增9% 。以此类推，计算18年
3) 金额10000元，第一年递增5% 第2年递增7%，第三年递增9%，以此类推，共计算18年
有没最简单的写法。只有23分，晕

Answer 1

参考：
年均增长率=报告期/基期^1/N-1,其中:1/N为开N次方,N为报告期与基期间隔的年限,如2006年-2009年,N=3,报告期是2009年的数据,基期为2006年的数据.

Answer 2

固定3年5%增加的using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;namespace KEVIN.Test
{
    class Program
    {
        static void Main(string[] args)
        {
            double s = Sum(5);
            Console.WriteLine(s);            Console.Read();
        }        public static double Sum(int count)
        {
            double sum = 0;
            for (int i = 0; i < count; i++)
            {
                sum += FixedFive(i);
            }
            return sum;
        }        public static double FixedFive(double pos)
        {
            double i = 1.05;
            if (pos == 1 || pos == 0 ) {
                return 10000;
            }
            if (pos%3 == 0)
            {
                return FixedFive(pos - 1) * i;
            }
            double res = FixedFive(pos - 1) ;
            return res;
        }    }
}

Answer 3

double ini = 10000;                double d1 = ini * Math.Pow(1.05, 6);//初始值乘以1.05的6次方.
                double d2 = ini;
                for (int i = 0; i < 6; i++)
                {
                    d2 = d2 * (1.05 + 0.02 * i);
                }                double d3 = ini;
                for (int i = 0; i < 18; i++)
                {
                    d3 = d3 * (1.05 + 0.02 * i);
                }
d1,d2,d3.三种情况

Answer 4

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;namespace KEVIN.Test
{
    class Program
    {
        static void Main(string[] args)
        {
            double s = SumFixed(18);
            Console.WriteLine(s);            s = SumSetp(18);
            Console.WriteLine(s);            s = SumSetpPreYear(18);
            Console.WriteLine(s);
            Console.Read();
        }        /// <summary>
        /// 每年递增  5% 7% 9%
        /// </summary>
        /// <param name="count"></param>
        /// <returns></returns>
        public static double SumSetpPreYear(int count)
        {
            double sum = 0;
            for (int i = 0; i < count; i++)
            {
                sum += SetpUpPreYear(i);
            }
            return sum;
        }        public static double SetpUpPreYear(double pos)
        {
            double i = 1.05;
            if (pos == 1 || pos == 0)
            {
                return 10000;
            }
            double res = SetpUpPreYear(pos - 1) * (i + 0.02 * (pos - 2));
            return res;
        }
        /// <summary>
        /// 每三年递增  5% 7% 9%
        /// </summary>
        /// <param name="count"></param>
        /// <returns></returns>
        public static double SumSetp(int count)
        {
            double sum = 0;
            for (int i = 0; i < count; i++)
            {
                sum += SetpUp(i);
            }
            return sum;
        }
       
        public static double SetpUp(double pos)
        {
            double i = 1.05;
            if (pos == 1 || pos == 0 ) {
                return 10000;
            }
            if (pos%3 == 0)
            {
                return SetpUp(pos - 1) * (i + 0.02 * (pos / 3 - 1));
            }
            double res = SetpUp(pos - 1);
            return res;
        }        /// <summary>
        /// 每三年固定递增  5%
        /// </summary>
        /// <param name="count"></param>
        /// <returns></returns>
        public static double SumFixed(int count)
        {
            double sum = 0;
            for (int i = 0; i < count; i++)
            {
                sum += FixedFive(i);
            }
            return sum;
        }        public static double FixedFive(double pos)
        {
            double i = 1.05;
            if (pos == 1 || pos == 0)
            {
                return 10000;
            }
            if (pos % 3 == 0)
            {
                return FixedFive(pos - 1) * i;
            }
            double res = FixedFive(pos - 1);
            return res;
        }    }
}

Answer 5

  private double getRealNumber(int year, double money)
        {
            //float defaultLV = 0.001F;
            computeMoney(year, ref money);
            return money;
            
          
        }        private void computeMoney(int year, ref double money)
        {
            if (year / 3 > 0)
            {
                money = money * (1 + 0.05);
                computeMoney(year - 3,ref money);
            }
            else
            {
                return;
            }
        }
没有仔细想

Answer 6

忘记利率会变了该下
    private double getRealNumber(int year, double money)
        {
            //float defaultLV = 0.001F;            computeMoney(year, ref money,0.05);
            return money;
            
          
        }        private void computeMoney(int year, ref double money,double lv)
        {
            if (year / 3 > 0)
            {
                money = money * (1 + lv);
                computeMoney(year - 3,ref money,lv+0.02);
            }
            else
            {
                return;
            }
        }