分段故障(堆芯转储）-矢量

我正在研究一种可以使用基本线段计算曲线长度的算法。所以若我有曲线的x和y坐标的向量，我需要计算这个基本线段的数量。为此，我发明了自己的递归算法。有一个代码：

#include <iostream>
#include <vector>
#include <cmath>
using namespace std;
//***********************************************
inline double Pitagoras(double xp, double yp, double xf, double yf)
{
    return sqrt((xp - xf)*(xp - xf) + (yp - yf)*(yp - yf));
}
//***************************************************
inline double calculateX(double xp, double yp, double a, double b, const double eps)
{
   double delta;
   double x1, x2;
     delta = (-2.0 * xp + 2.0 *a*b - 2.0 *a*yp)*(-2.0 * xp + 2.0 *a*b - 2.0 *a*yp)
        - 4.0* (1.0 + a*a)*(xp*xp + yp*yp + b*b - 2.0*b*yp - eps*eps);
     x1 = (-(-2.0 * xp + 2.0 *a*b - 2.0 *a*yp) - sqrt(delta))/(2.0 * (1.0 + a*a));
     x2 = (-(-2.0 * xp + 2.0 *a*b - 2.0 *a*yp) + sqrt(delta))/(2.0 * (1.0 + a*a));
   if(x1 >= xp)
     return x1;
     else
       return x2;
}
//***************************************************
inline double calculateY(double x, double a, double b)
{
  return a*x + b;
}
//***********************************************
unsigned long algorithmKolmogorow(double xp, double yp, double xf,
double yf, const double eps, vector<double> &vectorX, vector<double> &vectorY);
//***********************************************
int main()
{
    vector<double> vctrY; //vector of value of function
    vector<double> vctrX; //vector of x
    double xP,yP,xF,yF; //coordinates of two points on the curve
    const double Eps = 0.0001; //length of elementary line
      for(double x=1.0; x<=5 ;x +=0.001)
        {
          vctrX.push_back(x);
          vctrY.push_back(x*x); //f(x) = x^2
        }
    xP = vctrX[0];
    yP = vctrY[0];
    xF = vctrX[1];
    yF = vctrY[1]; //set beginning value
    cout<<algorithmKolmogorow(xP, yP, xF, yF, Eps, vctrX, vctrY)*Eps;
    return 0;
}
//***************************************************
unsigned long algorithmKolmogorow(double xp, double yp, double xf,
 double yf, const double eps, vector<double> &vectorX, vector<double> &vectorY)
{
    static unsigned long N; //licznik
    static unsigned long i = 1;
    double d;
    double a,b;
      d = Pitagoras(xp, yp, xf, yf);
         if(d >= eps){
            a = (yf - yp)/(xf - xp);
            b = yp - a*xp;
            xp = calculateX(xp, yp, a, b, eps);
            yp = calculateY(xp, a, b);
            N++;
         }
           else{
             i++;
             xf = vectorX[i];
             yf = vectorY[i];
             //cout<<i<<"t"<<vectorX[i]<<"t"<<vectorY[i]<<endl;
           }
             if(i < vectorX.size())
              N =  algorithmKolmogorow(xp, yp, xf, yf, eps, vectorX, vectorY);
return N;
}

正如你所看到的，主要是，我正在为抛物函数设置x，y坐标。当Eps很大时，例如Eps=0.001，一切都正常。如果我设置了一个较小的值，比如Eps=0.0001，那么我就会出现主题中的错误，程序就会停止运行。我完全不知道为什么。

我可以添加任何你需要的新信息(关于我的编译器，IDE，操作系统等(。

阵风