Welcome Guest.
No account yet? Register
Who's Online
We have 44 guests online

You are here:
 EH-Net
May 18, 2013, 05:20:27 PM
 Welcome, Guest. Please login or register.Did you miss your activation email? 1 Hour 1 Day 1 Week 1 Month Forever Login with username, password and session length
 News: Go back to The Ethical Hacker Network Online Magazine Home Page
 Home Help Calendar Login Register
 Pages: [1]   Go Down
 Author Topic: Any got a solution for this programming challenge ?  (Read 2408 times) 0 Members and 1 Guest are viewing this topic.
manoj9372
Jr. Member

Offline

Posts: 72

 « on: January 22, 2013, 09:57:35 AM »

hi guys,
here is challenge i got from my friend,i just want to know there is a solution available for this task,

when i enter a number it should display it's equivalent binary number like for 2 = 0010 3=0011,
but the important restriction is "IT SHOULD NOT USE/INVOKE MULTIPLICATION OR DIVISION OF ANY FORM" inside the computer.

is there a solution possible ?

if any one has one please post here...

 Logged
Dark_Knight
Sr. Member

Offline

Posts: 292

 « Reply #1 on: January 22, 2013, 10:33:16 AM »

Yes..we won't do your homewrok for you

.....just messing with you...
 « Last Edit: January 22, 2013, 10:34:54 AM by Dark_Knight » Logged

CEH, OSCP, GPEN, GWAPT, GCIA
http://sector876.blogspot.com
hayabusa
Hero Member

Offline

Posts: 1630

 « Reply #2 on: January 22, 2013, 10:41:34 AM »

Depends on the language...  It's simple in python...

As of version 2.3

bin(x)
Convert an integer number to a binary string. The result is a valid Python expression. If x is not a Python int object, it has to define an __index__() method that returns an integer.

You'd just need to strip off the first two characters of the return, such as:

Code:
val=bin(8);
newval=val.replace("0b", "");
print newval;

Now, we'll assume that the bin() uses multiplication / division inside of itself, so if you really wanted to do this, without ANY, you'd likely need to create an array of values, during runtime, where you GIVE it the values, and parse the array to return them.  That's if he's TRULY not allowing the use of the builtin functions of python to do the work...
 « Last Edit: January 22, 2013, 10:45:18 AM by hayabusa » Logged

~ hayabusa ~

"All men can see these tactics whereby I conquer, but what none can see is the strategy out of which victory is evolved." - Sun Tzu, 'The Art of War'

OSCE, OSCP , GPEN, C|EH
unicityd
Full Member

Offline

Posts: 156

Bored IT Manager, Crypto Nerd

 « Reply #3 on: January 22, 2013, 10:46:05 AM »

Depends on the language...  It's simple in python...

As of version 2.3

bin(x)

I think the point of the challenge is to do it manually.  The easiest way I can think of off-hand is to use a logical AND to test if each bit is set.
 Logged

BS in IT, CISSP, MS in IS Management (in progress)
H1t M0nk3y
Hero Member

Offline

Posts: 864

 « Reply #4 on: January 22, 2013, 11:13:10 AM »

Quote
"IT SHOULD NOT USE/INVOKE MULTIPLICATION OR DIVISION OF ANY FORM" inside the computer.
The important part is "inside the computer". In python, the bin() function might use multiplications and/or divisions.

You can always have a whole bunch of "if" statements. That's not elegant, but it would work for sure:

Code:
int number;

//Set the value of the "number" variable somehow

if(number == 0){
return "0000";
}
else if(number == 1){
return "0001";
}
else if(number == 2){
return "0010";
}
...

You can also fake multiplications with for loops:
Code:
int number1;
int number2;
int result = 0;

//Set the value of the "number1" and "number2" here

for(int i=0; i<number1; i++){

result = result + number2;
}

return result;

 « Last Edit: January 22, 2013, 11:19:39 AM by H1t M0nk3y » Logged

OSCP, GPEN, GWAPT, GSEC, CEH, CISSP
hayabusa
Hero Member

Offline

Posts: 1630

 « Reply #5 on: January 22, 2013, 11:19:00 AM »

I think unicityd's method is likely what they want.

@H1tM0nk3y...  That's why I put my extra 2 bits in, at the end, and noted adding values in the array.  You could simply create an array with all the values in order, then call from the positions, etc.

But really, I think unicityd's method is what they probably wanted.
 Logged

~ hayabusa ~

"All men can see these tactics whereby I conquer, but what none can see is the strategy out of which victory is evolved." - Sun Tzu, 'The Art of War'

OSCE, OSCP , GPEN, C|EH
manoj9372
Jr. Member

Offline

Posts: 72

 « Reply #6 on: January 24, 2013, 02:20:50 AM »

To the first guy
i am not a school kid
we need this logic to show that in REAL LIFE that program can produce much faster results than the hardware,that is the main task of this program and TBH i am not a programmer

And guys when i asked for solutions for this program from other programmers they urged me to use some kind of bit shifting to do this,
and it seems "unicityd" points were right...

 Logged
H1t M0nk3y
Hero Member

Offline

Posts: 864

 « Reply #7 on: January 24, 2013, 06:42:49 AM »

Ok, ok, I agree, unicityd has a better solution than me...

I have way too many things on my plate right now to spend cycles on this.

Being a developer, I believe that CPUs and RAM are way cheaper than developer's time (at least, most of the time).

Good luck and please post your solution!
 Logged

OSCP, GPEN, GWAPT, GSEC, CEH, CISSP
 Pages: [1]   Go Up

 Powered by SMF 1.1.18 | SMF © 2013, Simple MachinesJoomla Bridge by JoomlaHacks.com
Page created in 0.09 seconds with 23 queries.

Exclusive Deal

5% Off w/ Code: EHN_5

SANS Deals 4 EH-Netters
5% OFF Any SANS Course in Any Format!
Coupon Code: EHN_5 Including SANS Rocky Mountain 2013 & SANS Boston 2013
Polls
Compared to this year, 2013 will be:
 Great! Better. About the same. Little worse. FUBAR!

Recent Forum Topics
EH-Net News Feeds