두 줄이 교차하는지 테스트하기 위해 위의 기본 요소 아래에서 사용하는 C++ 프로그램

다음은 두 줄의 교차 여부를 테스트하기 위해 위의 기본 요소 아래에서 사용하는 C++ 프로그램입니다. 선이 선분과 교차하는지 여부를 테스트하는 데 사용할 수 있습니다. 세그먼트의 한 끝점이 선 왼쪽에 있고 다른 끝점이 오른쪽에 있는 경우에만 수행됩니다.

알고리즘

Begin
   For generating equation of the first line, generate random numbers for coefficient of x and y by using rand at every time of compilation.
   For generating equation of the second line, generate random numbers for coefficient of x and y by using rand at every time of compilation.
   Find the segment of line 1 as Y1.
   if (Y1 < 0)
      Find the segment of line 2
   if (Y2 >= 0)
      print they are intersecting.
   else if (Y2 < 0)
      print they are not intersecting.
   else if (Y1 >0)
      Find the segment of line 2
   if (Y2 <= 0)
      print they are intersecting.
   else if (Y2 >0)
      print they are not intersecting.
End.

예시 코드

#include<time.h>
#include<stdlib.h>
#include<iostream>
#include<math.h>

using namespace std;
const int L = 2;
const int H= 20;
int main(int argc, char **argv) {
   time_t s;
   time(&s);
   srand((unsigned int) s);

   int x1, x2, y1, y2;
   x1 = rand() % (H - L+ 1) + L;
   x2 = rand() % (H - L+ 1) + L;
   y1 = rand() % (H- L+ 1) + L;
   y2 = rand() % (H - L + 1) + L;

   cout << "The Equation of the 1st line is : (" << (y2 - y1) << ")x+(" << (x1 - x2) << ")y+(" << (x2 * y1 - x1 * y2) << ") = 0\n";

   int p1, p2, q1, q2;
   p1 = rand() % (H- L+ 1) + L;
   p2 = rand() % (H- L + 1) + L;
   q1 = rand() % (H - L + 1) + L;
   q2 = rand() % (H - L + 1) + L;

   cout << "The Equation of the 2nd line is : (" << (q2 - q1) << ")x+(" << (p1 - p2) << ")y+(" << (p2 * q1 - p1 * q2) << ") = 0\n";

   int Y1 = (y2 - y1) * p1 + (x1 - x2) * q1 + (x2 * y1 - x1 * y2); //Y1 segment
   if (Y1 < 0) {
      int Y2 = (y2 - y1) * p2 + (x1 - x2) * q2 + (x2 * y1 - x1 * y2); //Y2 segment
   if (Y2 >= 0)
      cout << "Lines are intersecting";
   else if (Y2 < 0)
      cout << "Lines are not intersecting";
   } else if (Y1 >0) {
      int Y2 = (y2 - y1) * p2 + (x1 - x2) * q2 + (x2 * y1 - x1 * y2);
      if (Y2 <= 0)
         cout << "Lines are intersecting";
      else if (Y2 >0)
         cout << "Lines are not intersecting";
   } else
      cout << "The point lies on the line";
   return 0;
}

출력

The Equation of the 1st line is : (-3)x+(2)y+(1) = 0
The Equation of the 2nd line is : (-5)x+(-5)y+(130) = 0
Lines are intersecting


The Equation of the 1st line is : (-1)x+(7)y+(-15) = 0
The Equation of the 2nd line is : (-4)x+(4)y+(-8) = 0
Lines are not intersecting