Line Clipping in CG using C

//Line Clipping
#include<stdio.h>
#include<conio.h>
#include<graphics.h>
void main()
{
 int gd=DETECT,gm;
 int x1,y1,x2,y2;
 int a1,b1,c1,d1;
 int a2,b2,c2,d2;
 int a3,b3,c3,d3;
 int x,y;
 initgraph(&gd,&gm,"C:\\TurboC3\\BGI");
 x=getmaxx();y=getmaxy();
 printf("Enter the starting coordinates of rectangle\n");
 scanf("%d%d",&x1,&y1);
 printf("Enter the end coordinates of rectangle\n");
 scanf("%d%d",&x2,&y2);
 rectangle(x1,y1,x2,y2);
 printf("Enter the start and end coordinates for 1st line\n");
 scanf("%d%d%d%d",&a1,&b1,&c1,&d1);
 printf("Enter the start and end coordinates for 2nd line\n");
 scanf("%d%d%d%d",&a2,&b2,&c2,&d2);
 printf("Enter the start and end coordinates for 3rd line\n");
 scanf("%d%d%d%d",&a3,&b3,&c3,&d3);
 line(a1,b1,c1,d1);
 line(a2,b2,c2,d2);
 line(a3,b3,c3,d3);
 getch();
 setfillstyle(1,BLACK);
 bar(0,0,x,y1-1);
 bar(0,0,x1-1,y);
 bar(x2+1,0,x,y);
 bar(0,y2+1,x,y);
 getch();
 closegraph();
}