Program to illustrate the implementation of 3D Rotation Transformation along x-axis

 # include <iostream.h>
 # include <graphics.h>
 # include    <conio.h>
 # include     <math.h>


 # define  f                 0.3
 # define  projection_angle   45


 void show_screen( );

 void apply_rotation_along_x_axis(constint [5][3],constint);
 void multiply_matrices(constfloat[4],constfloat[4][4],float[4]);

 void draw_pyramid(int [5][3]);
 void get_projected_point(int&,int&,int&);

 void Line(constint,constint,constint,constint);


 int main( )
    {
       int driver=VGA;
       int mode=VGAHI;

       initgraph(&driver,&mode,"..\\Bgi");

       show_screen( );

       int pyramid[5][3]={
                {280,130,50},      //  base front left
                {360,130,50},      //  base front right
                {360,130,-50},     //  base back right
                {280,130,-50},     //  base back left
                {320,20,0}        //  top
             };

      setcolor(15);
     draw_pyramid(pyramid);

       setcolor(15);
       settextstyle(0,0,1);
     outtextxy(50,415,"*** Use + & - Keys to apply Rotation along x-axis.");

       int angle=0;
       int key_code=0;

       char Key=NULL;

       do
      {
         Key=NULL;
         key_code=0;

         Key=getch( );
         key_code=int(Key);

         if(key_code==0)
        {
           Key=getch( );
           key_code=int(Key);
        }

         if(key_code==27)
        break;

         elseif(key_code==43)
        angle-=5;

         elseif(key_code==45)
        angle+=5;

         setfillstyle(1,0);
           bar(40,70,600,410);

         apply_rotation_along_x_axis(pyramid,angle);
      }
       while(1);

       return 0;
    }

 /*************************************************************************//*************************************************************************///------------------------  Funcion Definitions  ------------------------///*************************************************************************//*************************************************************************//*************************************************************************///-------------------  apply_rotation_along_x_axis( )  ------------------///*************************************************************************/void apply_rotation_along_x_axis(constint control_points[5][3],
                                constint theta)
    {
       int edge_points[5][3]={0};

       float angle=(theta*(M_PI/180));

       for(int count=0;count<5;count++)
      {
         edge_points[count][0]=control_points[count][0];
         edge_points[count][1]=control_points[count][1];
         edge_points[count][2]=control_points[count][2];

         float matrix_a[4]={edge_points[count][0],edge_points[count][1],
                            edge_points[count][2],1};
         float matrix_b[4][4]={
                    { 1,0,0,0 } ,
                    { 0,cos(angle),sin(angle),0 } ,
                    { 0,-sin(angle),cos(angle),0 } ,
                    { 0,0,0,1 }
                  };
         float matrix_c[4]={0};

         multiply_matrices(matrix_a,matrix_b,matrix_c);

         edge_points[count][0]=(int)(matrix_c[0]+0.5);
         edge_points[count][1]=(int)(matrix_c[1]+0.5);
         edge_points[count][2]=(int)(matrix_c[2]+0.5);
      }

       setcolor(10);
     draw_pyramid(edge_points);
    }

 /************************************************************************///----------------------  multiply_matrices( )  ------------------------///************************************************************************/void multiply_matrices(constfloat matrix_1[4],
                  constfloat matrix_2[4][4],float matrix_3[4])
    {
       for(int count_1=0;count_1<4;count_1++)
      {
         for(int count_2=0;count_2<4;count_2++)
        matrix_3[count_1]+=
               (matrix_1[count_2]*matrix_2[count_2][count_1]);
      }
    }

 /************************************************************************///--------------------------  draw_pyramid( )  -------------------------///************************************************************************/void draw_pyramid(int points[5][3])
    {
       int edge_points[5][3];

       for(int i=0;i<5;i++)
      {
         edge_points[i][0]=points[i][0];
         edge_points[i][1]=points[i][1];
         edge_points[i][2]=points[i][2];

         get_projected_point(edge_points[i][0],
                    edge_points[i][1],edge_points[i][2]);

         edge_points[i][1]+=240;
      }

       Line(edge_points[0][0],edge_points[0][1],
                      edge_points[1][0],edge_points[1][1]);
       Line(edge_points[1][0],edge_points[1][1],
                      edge_points[2][0],edge_points[2][1]);
       Line(edge_points[2][0],edge_points[2][1],
                      edge_points[3][0],edge_points[3][1]);
       Line(edge_points[3][0],edge_points[3][1],
                      edge_points[0][0],edge_points[0][1]);

       Line(edge_points[0][0],edge_points[0][1],
                      edge_points[4][0],edge_points[4][1]);
       Line(edge_points[1][0],edge_points[1][1],
                      edge_points[4][0],edge_points[4][1]);
       Line(edge_points[2][0],edge_points[2][1],
                      edge_points[4][0],edge_points[4][1]);
       Line(edge_points[3][0],edge_points[3][1],
                      edge_points[4][0],edge_points[4][1]);
    }

 /************************************************************************///---------------------  get_projected_point( )  -----------------------///************************************************************************/void get_projected_point(int& x,int& y,int& z)
    {
       float fcos0=(f*cos(projection_angle*(M_PI/180)));
       float fsin0=(f*sin(projection_angle*(M_PI/180)));

       float Par_v[4][4]={
                {1,0,0,0},
                {0,1,0,0},
                {fcos0,fsin0,0,0},
                {0,0,0,1}
             };

       float xy[4]={x,y,z,1};
       float new_xy[4]={0};

       multiply_matrices(xy,Par_v,new_xy);

       x=(int)(new_xy[0]+0.5);
       y=(int)(new_xy[1]+0.5);
       z=(int)(new_xy[2]+0.5);
    }

 /*************************************************************************///-------------------------------  Line( )  -----------------------------///*************************************************************************/void Line(constint x_1,constint y_1,constint x_2,constint y_2)
    {
       int color=getcolor( );

       int x1=x_1;
       int y1=y_1;

       int x2=x_2;
       int y2=y_2;

       if(x_1>x_2)
      {
         x1=x_2;
         y1=y_2;

         x2=x_1;
         y2=y_1;
      }

       int dx=abs(x2-x1);
       int dy=abs(y2-y1);
       int inc_dec=((y2>=y1)?1:-1);

       if(dx>dy)
      {
         int two_dy=(2*dy);
         int two_dy_dx=(2*(dy-dx));
         int p=((2*dy)-dx);

         int x=x1;
         int y=y1;

         putpixel(x,y,color);

         while(x<x2)
        {
           x++;

           if(p<0)
              p+=two_dy;

           else
              {
             y+=inc_dec;
             p+=two_dy_dx;
              }

           putpixel(x,y,color);
        }
      }

       else
      {
         int two_dx=(2*dx);
         int two_dx_dy=(2*(dx-dy));
         int p=((2*dx)-dy);

         int x=x1;
         int y=y1;

         putpixel(x,y,color);

         while(y!=y2)
        {
           y+=inc_dec;

           if(p<0)
              p+=two_dx;

           else
              {
             x++;
             p+=two_dx_dy;
              }

           putpixel(x,y,color);
        }
      }
    }

 /*************************************************************************///--------------------------  show_screen( )  ---------------------------///*************************************************************************/void show_screen( )
    {
       setfillstyle(1,1);
     bar(210,26,420,38);

       settextstyle(0,0,1);
     setcolor(15);
       outtextxy(5,5,"******************************************************************************");
       outtextxy(5,17,"*-**************************************************************************-*");
       outtextxy(5,29,"*-----------------------                             ------------------------*");
       outtextxy(5,41,"*-**************************************************************************-*");
       outtextxy(5,53,"*-**************************************************************************-*");

     setcolor(11);
       outtextxy(218,29,"3D Rotation along X-axis");

     setcolor(15);

       for(int count=0;count<=30;count++)
          outtextxy(5,(65+(count*12)),"*-*                                                                        *-*");

       outtextxy(5,438,"*-**************************************************************************-*");
       outtextxy(5,450,"*-------------------------                          -------------------------*");
       outtextxy(5,462,"******************************************************************************");

     setcolor(12);
       outtextxy(229,450,"Press any Key to exit.");
    }

Program that performs selection search(Linear Search)

#include <iostream.h>
#include <conio.h>

class sel_search
{
int d[50],s,search_val;
public:
void getdata(void);
int search(void);
void display(void);
};

void sel_search :: getdata(void)
{
cout<<endl<<endl;
cout<<"How many size of array you want to create:-";
cin>>s;
cout<<"Enter "<<s<<" Integers\n";
for(int i=0;i<s;i++)
    cin>>d[i];
cout<<"\n\nEnter your search:-";
cin>>search_val;
}

int  sel_search :: search(void)
{
for(int i=0;i<s;i++)
{
    if(d[i]==search_val)
           return(i+1);
}
return(-1);
}

void sel_search :: display(void)
{
int result;
cout<<"\n\n\n";
result=search();
if(result==-1)
    cout<<"\nEntered Search is Illegal\n";
else
    cout<<"\nSearch is Located at "<<result<<" Position";
}

void main()
{
clrscr();
sel_search o1;
o1.getdata();
o1.display();
getch();
}

Program to find the day of a week of a given date from 15 october 1582 to end of universe using arrays

 #include<iostream.h>
 #include<conio.h>


 int year_code(int,int);

 main()
    {
       clrscr();

       int date;
       int year;
       int month;
       int birth_week;
       int century;
       int birth_year;
       int century_remainder;
       int century_code;
       int birth_year_code;
       int day;

       cout<<"\n Enter the date in the following pattern :"<<endl;
       gotoxy(34,3);
       cout<<"Date - Month - Year"<<endl;

       gotoxy(39,4);
       cout<<"-       -       "<<endl;

       gotoxy(35,4);
       cin>>date;

       gotoxy(43,4);
       cin>>month;

       gotoxy(50,4);
       cin>>year;

       century=year/100;
       birth_year=year%100;

       century_remainder=century%4;

       if(century_remainder==0)
      century_code=date-1;

       elseif(century_remainder==1)
      century_code=date-3;

       elseif(century_remainder==2)
      century_code=date-5;

       else
      century_code=date;

       birth_year_code=year_code(birth_year,month);
       birth_week=century_code+birth_year_code;

       cout<<"\n The day on the given date is : ";

       day=birth_week%7;

       switch(day)
      {
         case 0: cout<<"Friday";
             break;

         case 1: cout<<"Saturday";
             break;

         case 2: cout<<"Sunday";
             break;

         case 3: cout<<"Monday";
             break;

         case 4: cout<<"Tuesday";
             break;

         case 5: cout<<"Wednesday";
             break;

         case 6: cout<<"Thursday";
             break;
      }

       getch();
       return 0;
    }

int year_code(int year,int month)
    {
       int code;

       int array_1[12]={3,6,6,2,4,7,2,5,1,3,6,1};
       int array_2[12]={4,7,7,3,5,1,3,6,2,4,7,2};
       int array_3[12]={5,1,1,4,6,2,4,7,3,5,1,3};
       int array_4[12]={6,2,3,6,1,4,6,2,5,7,3,5};
       int array_5[12]={1,4,4,7,2,5,7,3,6,1,4,6};
       int array_6[12]={2,5,5,1,3,6,1,4,7,2,5,7};
       int array_7[12]={3,6,6,2,4,7,2,5,1,3,6,1};
       int array_8[12]={4,7,1,4,6,2,4,7,3,5,1,3};
       int array_9[12]={6,2,2,5,7,3,5,1,4,6,2,4};
       int array_10[12]={7,3,3,6,1,4,6,2,5,7,3,5};
       int array_11[12]={2,3,1,2,4,7,2,5,1,3,6,1};
       int array_12[12]={7,3,4,7,2,5,7,3,6,1,4,6};
       int array_13[12]={5,1,2,5,7,3,5,1,4,6,2,4};
       int array_14[12]={3,6,7,3,5,1,3,6,2,4,7,2};
       int array_15[12]={1,4,5,1,3,6,1,4,7,2,5,7};

       if(year==1 || year==29 || year== 57 || year==85 || year==7 ||
     year==35 || year==63 || year==91 || year==18 || year==46 || year==74)
      code=array_1[month-1];

       elseif(year==2 || year==30 || year== 58 || year==86 || year==13 ||
     year==41 || year==69 || year==97 || year==19 || year==47 || year==75)
      code=array_2[month-1];

       elseif(year==3 || year==31 || year== 59 || year==87 || year==14 ||
     year==42 || year==70 || year==98 || year==25 || year==53 || year==81)
      code=array_3[month-1];

       elseif(year==4 || year==32 || year== 60 || year==88)
      code=array_4[month-12];

       elseif(year==5 || year==33 || year== 61 || year==89 || year==11 ||
     year==39 || year==67 || year==95 || year==22 || year==50 || year==78)
      code=array_5[month-1];

       elseif(year==6 || year==34 || year== 62 || year==90 || year==17 ||
             year==45 || year==73 || year==23 || year==51 || year==79)
      code=array_6[month-1];

       elseif(year==7 || year==35 || year== 63 || year==91)
      code=array_7[month-1];

       elseif(year==8 || year==36 || year==64 || year==92)
      code=array_8[month-1];

       elseif(year==9 || year==37 || year== 65 || year==93 || year==15 ||
     year==43 || year==71 || year==99 || year==26 || year==54 || year==82)
      code=array_9[month-1];

       elseif(year==10 || year==38 || year==66 || year==94 || year==21 ||
             year==49 || year==77 || year==27 || year==55 || year==83)
      code=array_10[month-1];

       elseif(year==12 || year==40 || year==68 || year==96)
      code=array_11[month-1];

       elseif(year==16 || year==44 || year==72 || year==100)
      code=array_12[month-1];

       elseif(year==20 || year==48 || year==76)
      code=array_13[month-1];

       elseif(year==24 || year==52 || year==80)
      code=array_14[month-1];

       elseif(year==28 || year==56 || year==84)
      code=array_15[month-1];

       return code;
    }

Flames in C++

#include<iostream.h>
#include<conio.h>
#include<string.h>
int main()
{
char n1[20],n2[20],a[20],b[20];
int i,j,k,tot=0;
cout<<"\n Enter the boy name  : ";
cin>>a;
cout<<"\n Enter the girl name : ";
cin>>b;
cout<<endl;
strcpy(n1,a);
strcpy(n2,b);
i=strlen(a);
j=strlen(b);
tot=i+j;
for(i=0;a[i]!=NULL;i++)
{
for(j=0;b[j]!=NULL;j++)
{
if(a[i]==b[j])
{
tot=tot-2;
b[j]='*';
break;
}
}
}
//cout<<"\n count = "<<tot<<endl;
if(tot == 2 ||tot== 4 || tot==7 ||tot==9 )
cout<<   n1 << " and " << n2 << " are Enemy";
else if( tot == 3 ||tot==5 || tot==14 ||tot==16 || tot==18 )
cout<<   n1 << " and " << n2 << " are Friends";
else if( tot == 8 || tot==12 || tot==17)
cout<<   n1 << " and " << n2 << " in Affection";
else if( tot == 10)
    cout<<   n1 << " and " << n2 << " Love";
    else if( tot == 6 || tot==11 || tot==15)
    cout<<   n1 << " and " << n2 << " will arriage";
    else
    cout<<   n1 << " and " << n2 << " are SweetHearts";
    getch();
return 0;
}