C Programming of DDA line drawing algorithm

#include<stdio.h>
#include<conio.h>
#include<graphics.h>
#include<ctype.h>
#include<math.h>
#include<stdlib.h>
void draw(int x1,int y1,int x2,int y2);
void main()
{
int x1,y1,x2,y2;
int gdriver=DETECT,gmode,gerror;
initgraph(&gdriver,&gmode,”c:\\tc\\bgi:”);
printf(“\n Enter the x and y value for starting point:\n”);
scanf(“%d%d”,&x1,&y1);
printf(“\n Enter the x and y value for ending point:\n”);
scanf(“%d%d”,&x2,&y2);
printf(“\n The Line is shown below: \n”);
draw(x1,y1,x2,y2);
getch();
}
void draw(int x1,int y1,int x2,int y2)
{
float x,y,xinc,yinc,dx,dy;
int k;
int step;
dx=x2-x1;
dy=y2-y1;
if(abs(dx)>abs(dy))
step=abs(dx);
else
step=abs(dy);
xinc=dx/step;
yinc=dy/step;
x=x1;
y=y1;
putpixel(x,y,1);
for(k=1;k<=step;k++)
{
x=x+xinc;
y=y+yinc;
putpixel(x,y,2);
}
}