dda

#include<iostream>
#include<libstdl>
#include<stdlib>
#include<conio>
#include<math>
#include<dos>
#include<stdio>

using namespace std;

class algo {
    public:
    float x,y,x1,y1,x2,y2,dx,dy,length;
    algo(float X1,float Y1,float X2,float Y2,float Dx,float Dy,float Length) {
        x1 = X1; x2 = X2; y1 = Y1, y2 = Y2; dx = Dx; dy = Dy; length = Length;
    }
    void drawline() {
        dx = (x2-x1)/length; dy = (y2-y1)/length; x = x1 + 0.5;
        y = y1 + 0.5;
        int i = 1;
        while(i++<=length) {
            putpixel(x,y,15); x += dx;
            y += dy;
        }
    }
};
void main()
{
    int i,gd = DETECT,gm=1; clrscr();
    float x1,y1,x2,y2,dx,dy,length;
    cout<<"Enter values x1,y1,x2,y2"<<endl; cin>>x1>>y1>>x2>>y2;

    initgraph(&gd,&gm,"C://TURBOC3//BGI");
    dx = abs(x2-x1); dy = abs(y2-y1);
    length = max(dx,dy);

    algo a(x1,y1,x2,y2,dx,dy,length);

    a.drawline();
}