最小二乘直线拟合

#include <iostream>
using namespace std;

int nihe(double *x,double *y,int N)
{
    double a0=0;
    double a1=0;

    double sum_x_square=0;
    double sum_x=0;
    double sum_y=0;
    double sum_x_y=0;
    double x_sum_square=0;

    for (int i=0;i<N;i++)
    {
        sum_x_square+=x[i]*x[i];
        sum_y+=y[i];
        sum_x+=x[i];
        sum_x_y+=x[i]*y[i];
    }
    x_sum_square=sum_x*sum_x;

    a0=((sum_x_square*sum_y)-(sum_x*sum_x_y))/(N*sum_x_square-x_sum_square);
    a1=((N*sum_x_y)-(sum_x*sum_y))/(N*sum_x_square-x_sum_square);
    
    cout<<a0<<endl;
    cout<<a1<<endl;
    return 0;
}


int main()
{
    double x[]={1,2,3,4,5};
    double y[]={1,3,3,5,5};

    int s;
    s=nihe(x,y,5);
    system("pause");
    return 0;

}