квадрат 2 (12)

#include <iostream>
#include <cmath>
#include <algorithm>
#include <iomanip>

using namespace std;

struct direct
{
 double k = 0, b = 0;
 double parametr = 0;
};

struct vershina
{
  double x, y;
};

direct storona (vershina first, vershina second)
{
  direct stright;
  if(first.x - second.x != 0)
  {
    stright.k = (first.y - second.y)/(first.x - second.x);
    stright.b = first.y - stright.k*first.x;
  }
  else stright.parametr = first.x;

  return stright;
}

vershina result (direct one, vershina head, double dlina, int shet)
{
  vershina result;
  direct two;
  if (one.k != 0)
    two.k = -1/one.k;
  two.b = head.y - head.x*two.k;
  vershina times;

  times.x = head.x-1;
  times.y = two.k*times.x+two.b;

  times.x = head.x - times.x;
  times.y = head.y - times.y;

  double koeff = sqrt((dlina*dlina)/(times.x*times.x + times.y*times.y));

  if (shet == 0)
  {
    result.x = times.x*koeff;
    result.x = head.x - result.x;
    result.y = times.y*koeff;
    result.y = head.y - result.y;
  }
  else
  {
    result.x = times.x*koeff;
    result.x = head.x + result.x;
    result.y = times.y*koeff;
    result.y = head.y + result.y;
  }

  return result;
}

int main ()
{
  vershina A, B, C, D;
  cin >> A.x >> A.y >> C.x >> C.y;
  direct AC, DB;

  double dlina = sqrt((A.x - C.x)*(A.x - C.x) + (A.y - C.y)*(A.y - C.y));

  AC = storona (A, C);

  vershina seredina_AC;
  seredina_AC.x = (A.x + C.x)/2;
  seredina_AC.y = (A.y + C.y)/2;

  B = result(AC, seredina_AC, dlina/2, 0);

  D = result(AC, seredina_AC, dlina/2, 1);

  cout << B.x << " " << B.y << endl;
  cout << D.x << " " << D.y << " ";
}