计算 1 + 1!/X + 2!/X^2 + … + N!/X^N

Question

大家好，我试图用 C# 编写一个程序来计算 1 + 1!/X + 2!/X^2 + … + N!/X^N 但它给出了错误的结果我尝试调试它但不能找出错误谁能帮我解决这个问题？

Console.WriteLine("Calculate 1 + 1!/X + 2!/X^2 + … + N!/X^N");
    Console.Write("N:");
    double n = double.Parse(Console.ReadLine());
    Console.Write("X:");
    double x = double.Parse(Console.ReadLine());
    double result = 1;
    int ifac = 1;
    for (int i = 1; i <= n; i++)
    {
        for (int j = i; j >= 1; j--)
        {
            ifac *= j;
        }
        result += ifac / Math.Pow(x, i);
    }
    Console.WriteLine(result);

Answer 1

您需要在每个循环中添加ifac = 1;。

Console.WriteLine("Calculate 1 + 1!/X + 2!/X^2 + … + N!/X^N");
Console.Write("N:");
double n = double.Parse(Console.ReadLine());
Console.Write("X:");
double x = double.Parse(Console.ReadLine());
double result = 1;
int ifac = 1;
for (int i = 1; i <= n; i++)
{
    ifac = 1; //This line is very important
    for (int j = i; j >= 1; j--)
    {
        ifac *= j;
    }
    result += ifac / Math.Pow(x, i);
}
Console.WriteLine(result);

计算 1 + 1!/X + 2!/X^2 + … + N!/X^N

Calculate 1 + 1!/X + 2!/X^2 + … + N!/X^N

c#

for-loop

calculator