Неправильно выводит результат при нахождении расстояния между отрезками

#include<iostream>
using namespace std;
 
double skalar(double x1, double y1, double x2, double y2)
{
    return  (x1*x2 + y1*y2);
}
 
int main()
{
    double x1, x2, x3, x4, y1, y2, y3, y4, x, y,l;
    int i, k, s;
 
    double a[4];
    double b[4]; 
    double c[4];
    double d[4];
 
    cin >> x1 >> y1 >> x2 >> y2 >> x3 >> y3 >> x4 >> y4;
    a[0] = x2-x1;
    a[1] = y2-y1;
 
    b[0] = x3-x2;
    b[1] = y3-y2;
 
    c[0] = x3-x4;
    c[1] = y3-y4;
 
 
    y = (-((x4 - x2)*(x2 - x1) + (y4 - y2)*(y2 - y1))  *  ((x2 - x1)*(x3 - x4) + (y2 - y1)*(y3 - y4))    - ((x2 - x1)*(x2 - x1) + (y2 - y1)*(y2 - y1))*((x2 - x1)*(x3 - x4) - (y4 - y2)*(y3 - y4))) / (((x3 - x4)*(x2 - x1) + (y3 - y4)*(y2 - y1))*((x3 - x4)*(x2 - x1) + (y3 - y4)*(y2 - y1)) - (((y3 - y4)*(y3 - y4) + (x3 - x4)*(x3 - x4)) *((x2 - x1)*(x2 - x1) + (y2 - y1)*(y2 - y1))));
    x = (-(x4 - x2)*(x3 - x4) - (y4 - y2)*(y3 - y4) - y*((y3 - y4)*(y3 - y4) + (x3 - x4)*(x3 - x4))) / ((x2 - x1)*(x3 - x4) + (y2 - y1)*(y3 - y4));
 
 
    a[0] = x*(x2 - x1);
    a[1] = x*(y2 - y1);
    c[0] = y*(x3 - x4);
    c[1] = y*(y3 - y4);
 
l = sqrt((c[0] - a[0])*(c[0] - a[0]) + (c[1] - a[1])*(c[1] - a[1]));
    cout << l;
    system("pause");
 
    
 
 
}