#include< conio.h >

#include< stdio.h >

#include< process.h >

void main()

{

FILE *fp;

char c;

clrscr();

printf("Contents of the file =>\n");

fp=fopen("demo.txt","r");

while(!feof(fp))

{

c=fgetc(fp);

printf("%c",c);

 }

fp=fopen("demo.txt","a");

if(fp==NULL)

{

printf("file can't append\n");

exit(1);

}

printf("\nEnter the string to append\n");

while(c!='.')

{

c=getche();

fputc(c,fp);

}

fclose(fp);

printf("file contents after appending\n");

fp=fopen("demo.txt","r");

while(!feof(fp))

{

c=fgetc(fp);

printf("%c",c);

}

}

----------------------------------------------------------

OUT PUT:

----------------------------------------------------------

Contents of the file =>

This is c prorgam.

Enter the string to append

I upload C++ prorams soon.

File contents after appending

This is c prorgam.I upload C++ prorams soon.

#include< stdio.h >

#include< conio.h >

#include< stdlib.h >

void main()

 {

FILE *fs,*ft;

char ch;

clrscr();

 fs = fopen("file1.txt","r");

 if(fs==NULL)

  {

 printf("Cannot open source file ! Press key to exit.");

 getch();

 exit(0);

  }

ft = fopen("file2.txt","w");

 if(ft==NULL)

{

printf("Cannot copy file !");

 fclose(fs);

 getch();

 exit(0);

 }

while(1)

 {

ch = getc(fs);

if(ch==EOF)

{

 break;

}

else

putc(ch,ft);

}

printf("File copied succesfully!");

fclose(fs);

fclose(ft);

}

----------------------------------------------------------

OUT PUT:

----------------------------------------------------------

File copied successfully!

#include< conio.h >

#include< stdio.h >

#include

void main()

{

FILE *fp;

char c;

clrscr();

fp=fopen("demo.txt","w");

if(fp==NULL)

{

printf("can't open file\n");

exit(1);

}

printf("write data and to stop press =>'.'\n");

while(c!='.')

{

c=getche();

fputc(c,fp);

}

fclose(fp);

printf("\n Read Data from File =>\n");

fp=fopen("demo.txt","r");

while(!feof(fp))

printf("%c",getc(fp));

getch();

}

----------------------------------------------------------

OUT PUT:

----------------------------------------------------------

Write data and to stop press => ’.’

C Programs.

 Read Data from File =>

C Programs.

#include< iostream.h >

#include< conio.h >

class item

{                                                                                          

private:

int a,b,c,d;

public:

void get();

void multiply();

void sum();

};

void item::get()

{

cout<<"enter a & b :" ;

cin>>a>>b;

}

void item::sum()

{

c=a+b;

cout<<"\n sum is"<< c;

}

void item::multiply()

{

d=a*b;

cout<<"\n multiplication is "<< d;

}

void main()

{

clrscr();

item t;

t.get();

t.sum();

t.multiply();

getch();

}

-------------------------------------------------------

Out put

-------------------------------------------------------

Enter a & b : 5

4

Sum is 9

Multiplication is 20

Tower of hanoi is a historical problem, which can be easily expressed using recursion. There are N disks of decreasing size stacked on one needle, and two other empty needles. It is required to stack all the disks onto a second needle in the decreasing order of size. The third needle can be used as a temporary storage. The movement of the disks must confirm to the following rules,

1. Only one disk may be moved at a time
2. A disk can be moved from any needle to any other.
3. The larger disk should not rest upon a smaller one.

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

void move ( int, char, char, char ) ;

void main( )
{
    int n = 3 ;
    clrscr( ) ;
    move ( n, 'A', 'B', 'C' ) ;
    getch( ) ;
}

void move ( int n, char sp, char ap, char ep )
{
    if ( n == 1 )
        printf ("\nMove from %c to %c ", sp, ep ) ;
    else
    {
        move ( n - 1, sp, ep, ap ) ;
        move ( 1, sp, ' ', ep ) ;
        move ( n - 1, ap, sp, ep ) ;
    }
}