//Findin derivative in x point
private static double derivative(string rpnFunc, double x, List <string> variables)
{
//Making an array for x + derivative tolerance
double[] dx = new double[1];
dx[0] = x + 1E-12;
//Making an array for x point
double[] xArr = new double[1];
xArr[0] = x;
//Finding f(x) and f(x+dx)
double fxdx = RPN.CalculateRPN(rpnFunc, variables, dx);
double fx = RPN.CalculateRPN(rpnFunc, variables, xArr);
//Finding derivative
double result = (fxdx - fx) / 1E-12;
return(result);
}
static void Main(string[] args)
{
string newString = Console.ReadLine();
string resultSTR = RPN.toRPN(newString);
IEnumerable <string> stringList = RPN.findAllX(resultSTR);
double[] n = new double[stringList.Count()];
int i = 0;
foreach (string current in stringList)
{
n[i] = int.Parse(Console.ReadLine());
resultSTR = resultSTR.Replace(current, n[i].ToString());
i++;
}
Console.WriteLine(resultSTR);
Console.WriteLine(RPN.CalculateRPN(resultSTR, n));
}