DDA line drawing algorithm

    #include<stdio.h>
    #include<conio.h>
    #include<graphics.h>
    void main()
    {
    int x1,y1,x2,y2,dx,dy,length,i;
    float x,y,xinc,yinc;
    int gd=DETECT,gm;
    //clrscr();
    //gd=DETECT;
    initgraph(&gd,&gm,"c:\\tc\\bgi");
     printf("Enter the starting coordinates");
    scanf("%d%d",&x1,&y1);
    printf("Enter the ending coordinates");
    scanf("%d%d",&x2,&y2);
    dx=x2-x1;
    dy=y2-y1;
    if(abs(dx)>abs(dy))
    length=abs(dx);
    else
    length=abs(dy);
    xinc=dx/(float)length;
    yinc=dy/(float)length;
    x=x1
    y=y1
    putpixel(x,y,10);
    for(i=0;i<length;i++)
    {
    putpixel(x,y,10);
    x=x+xinc;
    y=y+yinc;
    delay(10);
    }
    getch();
    closegraph();
    }