Given three points (x1, y1), (x2, y2) and (x3, y3), write a program to check if all the three points fall on one straight line.

 #include<iostream>
 using namespace std;
 #include<conio.h>
 int main()
{
  int x1,y1,x2,y2,x3,y3,slope1,slope2;

 cout<<"Enter coordinates of 1st point (x1,y1) : ";
  scanf("%d%d",&x1,&y1);
 cout<<"Enter coordinates of 2nd point (x2,y2) : ";
  cin>>x2>>y2;
 cout<<"Enter coordinates of 3rd point (x3,y3) : ";
  cin>>x3>>y3;
  slope1=(y2-y1)/(x2-x1);
  slope2=(y3-y2)/(x3-x2);
  if(slope1==slope2)
  {
   cout<<"The given point fall on one straight line.";
  }
  else
  {
   cout<<"The given point does not fall on one straight line.";
  }
  getch();
  return 0;
}