C - Program for Character Generation

#include<stdio.h>
#include<conio.h>
#include<graphics.h>
void main()
{
int gd=DETECT,gm,i,j;
int a[20][20]=
{{0,0,0,1,1,1,0,0,0,0,0,0,0,0,1,1,1,1,0,0},
{0,0,1,0,0,0,1,0,0,0,0,0,0,1,0,0,0,0,1,0},
{0,1,0,0,0,0,0,1,0,0,0,0,1,0,0,0,0,0,0,1},
{1,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0},
{1,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0},
{1,0,0,0,0,0,0,0,0,0,0,1,0,0,0,1,1,1,1,0},
{1,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,1,0},
{0,1,0,0,0,0,0,1,0,0,0,1,0,0,0,0,0,0,1,0},
{0,0,1,0,0,0,1,0,0,0,0,0,1,0,0,0,0,1,0,0},
{0,0,0,1,1,1,0,0,0,0,0,0,0,1,1,1,1,0,0,0}};


initgraph(&gd,&gm,"c:\\tc\\bgi");
for(i=0;i<19;i++)
{
for(j=0;j<19;j++)
{
if(a[i][j]==1)
putpixel(100+j,200+i,WHITE);
}
}
getch();
}

C - Program for Implementation of Mid-Point Ellipse Drawing Algorithm

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <time.h>
#include <dos.h>

int main(void)
{
int gd=DETECT,gm;
int cenx,ceny;
float Pk,a,b,x,y;
clrscr();

printf("\n\n Enter 'a' and 'b': ");
scanf("%f%f",&a,&b);

initgraph(&gd,&gm,"c:\\tc\\bgi");


cenx=getmaxx()/2;
ceny=getmaxy()/2;

Pk=b*b-b*a*a+0.25*a*a;
x=0;
y=b;
putpixel(cenx+x,ceny+y,WHITE);
putpixel(cenx+x,ceny-y,WHITE);
putpixel(cenx-x,ceny+y,WHITE);
putpixel(cenx-x,ceny-y,WHITE);

while (2*x*b*b <= 2*y*a*a)
{
if (Pk<0)
{
x=x+1;
y=y;
Pk=Pk+2*x*b*b+3*b*b;
}
else
{
x=x+1;
y=y-1;
Pk=Pk+2*x*b*b+3*b*b-2*y*a*a+2*a*a;
}
putpixel(cenx+x,ceny+y,WHITE);
putpixel(cenx+x,ceny-y,WHITE);
putpixel(cenx-x,ceny+y,WHITE);
putpixel(cenx-x,ceny-y,WHITE);
delay(40);
}


Pk=(x+0.5)*(x+0.5)*b*b+(y-1)*(y-1)*a*a-a*a*b*b;
putpixel(cenx+x,ceny+y,WHITE);
putpixel(cenx+x,ceny-y,WHITE);
putpixel(cenx-x,ceny+y,WHITE);
putpixel(cenx-x,ceny-y,WHITE);
while (y>0)
{
if (Pk>0)
{
x=x;
y=y-1;
Pk=Pk-2*y*a*a+3*a*a;
}
else
{
x=x+1;
y=y-1;
Pk=Pk-2*y*a*a+3*a*a+2*x*b*b+2*b*b;
}
putpixel(cenx+x,ceny+y,WHITE);
putpixel(cenx+x,ceny-y,WHITE);
putpixel(cenx-x,ceny+y,WHITE);
putpixel(cenx-x,ceny-y,WHITE);
delay(40);
}
gotoxy(1,25);
printf ("\npress any key to exit.");
getch();
closegraph();
return 0;
}

C - Program for Liang Barsky Line Clipping Algorithm

#include<graphics.h>
#include<dos.h>
#include<conio.h>
#include<stdlib.h>

void main()
{
int gd, gm ;
int x1 , y1 , x2 , y2 ;
int wxmin,wymin,wxmax, wymax ;
float u1 = 0.0,u2 = 1.0 ;
int p1 , q1 , p2 , q2 , p3 , q3 , p4 ,q4 ;
float r1 , r2 , r3 , r4 ;
int x11 , y11 , x22 , y22 ;
clrscr();
printf("Enter the windows left xmin , top boundry ymin\n");
scanf("%d%d",&wxmin,&wymin);
printf("Enter the windows right xmax ,bottom boundry ymax\n");
scanf("%d%d",&wxmax,&wymax);
printf("Enter line x1 , y1 co-ordinate\n");
scanf("%d%d",&x1,&y1);
printf("Enter line x2 , y2 co-ordinate\n");
scanf("%d%d",&x2,&y2);
printf("liang barsky express these 4 inequalities using lpk<=qpk\n");
p1 = -(x2 - x1 ); q1 = x1 - wxmin ;
p2 = ( x2 - x1 ) ; q2 = wxmax - x1 ;
p3 = - ( y2 - y1 ) ; q3 = y1 - wymin ;
p4 = ( y2 - y1 ) ; q4 = wymax - y1 ;
printf("p1=0 line is parallel to left clipping\n");
printf("p2=0 line is parallel to right clipping\n");
printf("p3=0 line is parallel to bottom clipping\n");
printf("p4=0 line is parallel to top clipping\n");

if( ( ( p1 == 0.0 ) && ( q1 < 0.0 ) ) ||
( ( p2 == 0.0 ) && ( q2 < 0.0 ) ) ||
( ( p3 == 0.0 ) && ( q3 < 0.0 ) ) ||
( ( p4 == 0.0 ) && ( q4 < 0.0 ) ) )
{
printf("Line is rejected\n");
getch();
detectgraph(&gd,&gm);
initgraph(&gd,&gm,"c:\\tc\\bgi");
setcolor(RED);
rectangle(wxmin,wymax,wxmax,wymin);
setcolor(BLUE);
line(x1,y1,x2,y2);
getch();
setcolor(WHITE);
line(x1,y1,x2,y2);
getch();
}
else
{
if( p1 != 0.0 )
{
r1 =(float) q1 /p1 ;
if( p1 < 0 )
u1 = max(r1 , u1 );
else
u2 = min(r1 , u2 );
}
if( p2 != 0.0 )
{
r2 = (float ) q2 /p2 ;
if( p2 < 0 )
u1 = max(r2 , u1 );
else
u2 = min(r2 , u2 );

}
if( p3 != 0.0 )
{
r3 = (float )q3 /p3 ;
if( p3 < 0 )
u1 = max(r3 , u1 );
else
u2 = min(r3 , u2 );
}
if( p4 != 0.0 )
{
r4 = (float )q4 /p4 ;
if( p4 < 0 )
u1 = max(r4 , u1 );
else
u2 = min(r4 , u2 );
}

if( u1 > u2 )
printf("line rejected\n");
else
{
x11 = x1 + u1 * ( x2 - x1 ) ;
y11 = y1 + u1 * ( y2 - y1 ) ;

x22 = x1 + u2 * ( x2 - x1 );
y22 = y1 + u2 * ( y2 - y1 );

printf("Original line cordinates\n");
printf("x1 = %d , y1 = %d, x2 = %d, y2 = %d\n",x1,y1,x2,y2);
printf("Windows coordinate are \n");
printf("wxmin = %d, wymin = %d,wxmax = %d , wymax = %d ",wxmin,wymin,wxmax,wymax);

printf("New coordinates are \n");
printf("x1 = %d, y1 = %d,x2 = %d , y2 = %d\n",x11,y11,x22,y22);
detectgraph(&gd,&gm);
initgraph(&gd,&gm,"C:\\TC\\BGI");
setcolor(2);
rectangle(wxmin,wymax,wxmax,wymin);
setcolor(1);
line(x1,y1,x2,y2);
getch();
setcolor(0);
line(x1,y1,x2,y2);
setcolor(3);
line(x11,y11,x22,y22);
getch();

}
}
}

C - Program for Cohen Sutherland Line Clipping Algorithm

#include<stdio.h>
#include<graphics.h>
#include<conio.h>

typedef unsigned int outcode;
enum { TOP=0x1, BOTTOM=0x2, RIGHT=0x4, LEFT=0x8 };

void lineclip(x0,y0,x1,y1,xwmin,ywmin,xwmax,ywmax )
float x0,y0,x1,y1,xwmin,ywmin,xwmax,ywmax;
{

int gd,gm;
outcode code0,code1,codeout;
int accept = 0, done=0;

code0 = calcode(x0,y0,xwmin,ywmin,xwmax,ywmax);
code1 = calcode(x1,y1,xwmin,ywmin,xwmax,ywmax);

do{
if(!(code0 | code1))
{ accept =1 ; done =1; }
else
if(code0 & code1) done = 1;
else
{
float x,y;
codeout = code0 ? code0 : code1;
if(codeout & TOP)
{
x = x0 + (x1-x0)*(ywmax-y0)/(y1-y0);
y = ywmax;
}
else
if( codeout & BOTTOM)
{
x = x0 + (x1-x0)*(ywmin-y0)/(y1-y0);
y = ywmin;
}
else
if ( codeout & RIGHT)
{
y = y0+(y1-y0)*(xwmax-x0)/(x1-x0);
x = xwmax;
}
else
{
y = y0 + (y1-y0)*(xwmin-x0)/(x1-x0);
x = xwmin;
}
if( codeout == code0)
{
x0 = x; y0 = y;
code0=calcode(x0,y0,xwmin,ywmin,xwmax,ywmax);
}
else
{
x1 = x; y1 = y;
code1 = calcode(x1,y1,xwmin,ywmin,xwmax,ywmax);
}
}
} while( done == 0);

if(accept) line(x0,y0,x1,y1);

rectangle(xwmin,ywmin,xwmax,ywmax);

getch();

}


int calcode (x,y,xwmin,ywmin,xwmax,ywmax)
float x,y,xwmin,ywmin,xwmax,ywmax;
{
int code =0;

if(y> ywmax)
code |=TOP;
else if( y<ywmin)
code |= BOTTOM;
else if(x > xwmax)
code |= RIGHT;
else if ( x< xwmin)
code |= LEFT;

return(code);
}


main()
{

float x2,y2,x1,y1,xwmin,ywmin,xwmax,ywmax;
int gd=DETECT,gm;

clrscr();
initgraph(&gd,&gm,"e:\\tc\\bgi");

printf("\n\n\tEnter the co-ordinates of Line :");

printf("\n\n\tX1 Y1 : ");
scanf("%f %f",&x1,&y1);

printf("\n\n\tX2 Y2 : ");
scanf("%f %f",&x2,&y2);


printf("\n\tEnter the co_ordinates of window :\n ");
printf("\n\txwmin , ywmin : ");
scanf("%f %f",&xwmin,&ywmin);
printf("\n\txwmax , ywmax : ");
scanf("%f %f",&xwmax,&ywmax);
clrscr();
line(x1,y1,x2,y2);
rectangle(xwmin,ywmin,xwmax,ywmax);
getch();
clrscr();


lineclip(x1,y1,x2,y2,xwmin,ywmin,xwmax,ywmax );
getch();
closegraph();

}

C - Program to Implement Flood Fill Algorithm

#include<conio.h>
#include<stdio.h>
#include<graphics.h>
#include<dos.h>

void fill_right(x,y)
int x , y ;
{
if(getpixel(x,y) == 0)
{
putpixel(x,y,RED);
fill_right(++x,y);
x = x - 1 ;
fill_right(x,y-1);
fill_right(x,y+1);

}
}

void fill_left(x,y)
int x , y ;
{
if(getpixel(x,y) == 0)
{
putpixel(x,y,RED);

fill_left(--x,y);
x = x + 1 ;
fill_left(x,y-1);
fill_left(x,y+1);

}
}


void main()
{
int x , y ,a[10][10];
int gd, gm ,n,i;

detectgraph(&gd,&gm);
initgraph(&gd,&gm,"c:\\tc\\bgi");

printf("\n\n\tEnter the no. of edges of polygon : ");
scanf("%d",&n);
printf("\n\n\tEnter the cordinates of polygon :\n\n\n ");

for(i=0;i<n;i++)
{
printf("\tX%d Y%d : ",i,i);
scanf("%d %d",&a[i][0],&a[i][1]);
}

a[n][0]=a[0][0];
a[n][1]=a[0][1];

printf("\n\n\tEnter the seed pt. : ");
scanf("%d%d",&x,&y);


cleardevice();
setcolor(WHITE);

for(i=0;i<n;i++) /*- draw poly -*/
{
line(a[i][0],a[i][1],a[i+1][0],a[i+1][1]);
}

fill_right(x,y);
fill_left(x-1,y);

getch();
}

/*SAMPLE INPUT*/
/*Enter the number of edges of polygon 4

X0 Y0 = 50 50
X1 Y1 = 200 50
X2 Y2 = 200 300
X3 Y3 = 50 300

Enter the seed point 100 100*/

C - Program to Implement Boundary Fill Algorithm

#include<stdio.h>
#include<conio.h>
#include<graphics.h>
#include<dos.h>



void fill_right(x,y)
int x , y ;
{
if((getpixel(x,y) != WHITE)&&(getpixel(x,y) != RED))
{
putpixel(x,y,RED);
fill_right(++x,y);
x = x - 1 ;
fill_right(x,y-1);
fill_right(x,y+1);
}
delay(1);
}


void fill_left(x,y)
int x , y ;
{
if((getpixel(x,y) != WHITE)&&(getpixel(x,y) != RED))
{
putpixel(x,y,RED);

fill_left(--x,y);
x = x + 1 ;
fill_left(x,y-1);
fill_left(x,y+1);
}
delay(1);
}


void main()
{
int x,y,n,i;
int gd=DETECT,gm;
clrscr();

initgraph(&gd,&gm,"c:\\tc\\bgi");



/*- draw object -*/

line (50,50,200,50);
line (200,50,200,300);
line (200,300,50,300);
line (50,300,50,50);

/*- set seed point -*/
x = 100; y = 100;

fill_right(x,y);
fill_left(x-1,y);

getch();
}

C - Program to Implement Bezier Curve Drawing Algorithm

#include<stdio.h>
#include<conio.h>
#include<graphics.h>

int x,y,z;

void main()
{
float u;
int gd,gm,ymax,i,n,c[4][3];
for(i=0;i<4;i++) { c[i][0]=0; c[i][1]=0; }
printf("\n\n Enter four points : \n\n");

for(i=0; i<4; i++)
{
printf("\t X%d Y%d : ",i,i);
scanf("%d %d",&c[i][0],&c[i][1]);
}

c[4][0]=c[0][0];
c[4][1]=c[0][1];

detectgraph(&gd,&gm);
initgraph(&gd,&gm,"e:\\tc\\bgi");

ymax = 480;

setcolor(13);
for(i=0;i<3;i++)
{
line(c[i][0],ymax-c[i][1],c[i+1][0],ymax-c[i+1][1]);
}

setcolor(3);
n=3;

for(i=0;i<=40;i++)
{
u=(float)i/40.0;
bezier(u,n,c);

if(i==0)
{ moveto(x,ymax-y);}
else
{ lineto(x,ymax-y); }
getch();
}
getch();
}
bezier(u,n,p)
float u;int n; int p[4][3];
{
int j;
float v,b;
float blend(int,int,float);
x=0;y=0;z=0;
for(j=0;j<=n;j++)
{
b=blend(j,n,u);
x=x+(p[j][0]*b);
y=y+(p[j][1]*b);
z=z+(p[j][2]*b);
}
}

float blend(int j,int n,float u)
{
int k;
float v,blend;
v=C(n,j);
for(k=0;k<j;k++)
{ v*=u; }
for(k=1;k<=(n-j);k++)
{ v *= (1-u); }
blend=v;
return(blend);
}

C(int n,int j)
{
int k,a,c;
a=1;
for(k=j+1;k<=n;k++) { a*=k; }
for(k=1;k<=(n-j);k++) { a=a/k; }
c=a;
return(c);
}

 C - Program without Main Function

#include<stdio.h>
#define decode(s,t,u,m,p,e,d) m##s##u##t
#define begin decode(a,n,i,m,a,t,e)int begin()
{
printf(” hello “);
}


Explanation -

C - Program for Guessing Game

#include<stdio.h>
#include<stdlib.h>
#include<time.h>

void main()
{
int num,guess=-1,tries=0,pass=0;
time_t t;
srand((unsigned)time(&t));
num=rand()%100;
while((guess!=num)&&tries<8)
{
printf("Enter the guess num b/w 0&100

(you have %d tries left out)\n",(8-tries)); 

scanf("%d",&guess);

tries++;
if(guess==num)
{
printf("Hurray you guessed it correctly!!!\n");

pass=1;
}

else if(num< guess)
printf("Your guess is too high\n");

else
printf("Your guess is too low\n");
}

if(pass==0)
printf("Sorry you lost! The correct number is %d\n",num);

} 

Self Destructing Program in C

#include<stdio.h>
#include<conio.h>
#include<dos.h>
void main()
{
printf("This program will destroy itself if u press any key!!!\n");
getch();
remove(_argv[0]);/*array of pointers to command line arguments*/
}

C - Program for Pigeon Breeding Problem

#include<stdio.h>
#include<process.h>

struct node
{
int age;
struct node *link;
};

typedef struct node* NODE; 

 NODE getnode()
{
NODE x;
x=(NODE)malloc(sizeof(struct node));
if(x==NULL)
{
printf(“Out of memory\n”);
exit(1);
}
return x;
}

void main()
{

unsigned long int count=1;
unsigned int months,i;
NODE first=getnode();/*this is the intial adult pair*/
first->age=2; /*assume the age of initial adult pair as 2*/
first->link=NULL;
printf(“Enter the no. of months\n”);
scanf(“%u”,&months);
for(i=0;iage>=2)&&(temp->age<=60)) { NODE temp1=getnode(); temp->age+=1;
temp1->age=1;
temp1->link=first;
first=temp1;
temp=temp->link;
++count;
}

else
{
temp->age+=1;
temp=temp->link;
}
}
}
printf(“Total no. of pairs after %u months=%ld\n”,months,count);
}

C - Program to Produce Sound of Specific Frequency

#include<dos.h>
 
main()
{
   int a;
 
   for ( a = 200 ; a <= 1000 ; a = a + 20 )
   {
      sound(a);
      delay(25);
   }
   nosound();
 
   return 0;
}

C - Program to Display Time

#include<stdio.h>
#include<dos.h>
 
main()
{
   struct time t;
 
   gettime(&t);
 
   printf("Current system time is %d : %d : %d\n",t.ti_hour,t.ti_min,t.ti_sec);
 
   return 0;
}

C - Program to Display Date

#include<stdio.h>
#include<dos.h>
 
main()
{
   struct date d;
 
   getdate(&d);
 
   printf("Current system date is %d/%d/%d\n",d.da_day,d.da_mon,d.da_year);
 
   return 0;
}

C - Program to Calculate Square Root of Given Number

#include <stdio.h>
#include <math.h>
 
int main()
{
 
  double n, result;
 
  printf("Enter a number to calculate it's square root\n");
  scanf("%lf", &n);
 
  result = sqrt(n);
 
  printf("Square root of %.2lf = %.2lf\n", n, result);
 
  return 0;
}

C - Program to Display Mouse Pointer in Graphics Mode

#include<graphics.h>
#include<conio.h>
#include<dos.h>
 
int initmouse();
void showmouseptr();
 
union REGS i, o;
 
main()
{
   int status, gd = DETECT, gm;
 
   initgraph(&gd,&gm,"C:\\TC\\BGI");
 
   status = initmouse();
 
   if ( status == 0 )
      printf("Mouse support not available.\n");
   else
      showmouseptr();
 
   getch();
   return 0;
}
 
int initmouse()
{
   i.x.ax = 0;
   int86(0X33,&i,&o);
   return ( o.x.ax );
}
 
void showmouseptr()
{
   i.x.ax = 1;
   int86(0X33,&i,&o);
}

C Program to Display Mouse Pointer in Textmode 

#include<dos.h>
#include<conio.h>
 
int initmouse();
void showmouseptr();
 
union REGS i, o;
 
main()
{
   int status;
 
   status = initmouse();
 
   if ( status == 0 )
      printf("Mouse support not available.\n");
   else
      showmouseptr();
 
   getch();
   return 0;
}
 
int initmouse()
{
   i.x.ax = 0;
   int86(0X33,&i,&o);
   return ( o.x.ax );
}
 
void showmouseptr()
{
   i.x.ax = 1;
   int86(0X33,&i,&o);
}