# How many?

• (3 Pages)
• 1
• 2
• 3

## 33 Replies - 14315 Views - Last Post: 24 October 2013 - 02:21 PM

### #1 AmuletOfNight

Reputation: 3
• Posts: 153
• Joined: 23-July 09

# How many?

Posted 04 June 2010 - 02:04 PM

If I use an algorithm that generates a serial that looks like #########-XX##

How many unique keys would this be able to create? Or would you need the algorithm?
Is This A Good Question/Topic? 0

## Replies To: How many?

• MrCupOfT

Reputation: 2298
• Posts: 9,535
• Joined: 29-May 08

## Re: How many?

Posted 04 June 2010 - 02:09 PM

1

### #3 AmuletOfNight

Reputation: 3
• Posts: 153
• Joined: 23-July 09

## Re: How many?

Posted 04 June 2010 - 02:14 PM

So that means you need the algorithm because it goes off their name?

### #4 raziel_

• Like a lollipop

Reputation: 469
• Posts: 4,281
• Joined: 25-March 09

## Re: How many?

Posted 04 June 2010 - 02:22 PM

assuming it is only from 9 digit numbers (for 1 to 9)
######### is 9^9 = 387 420 489
XX## is 9^4 = 6561 assuming all are digits only

i dont get it why 1?

This post has been edited by NoBrain: 04 June 2010 - 02:22 PM

• MrCupOfT

Reputation: 2298
• Posts: 9,535
• Joined: 29-May 08

## Re: How many?

Posted 04 June 2010 - 02:25 PM

generates a serial that looks like #########-XX##

If the output for algorithm is #########-XX## there can only be one.
To work of the number of combination you need to tell us what the symbols represent.

### #6 AmuletOfNight

Reputation: 3
• Posts: 153
• Joined: 23-July 09

## Re: How many?

Posted 04 June 2010 - 02:29 PM

NoBrain, on 04 June 2010 - 03:22 PM, said:

assuming it is only from 9 digit numbers (for 1 to 9)
######### is 9^9 = 387 420 489
XX## is 9^4 = 6561 assuming all are digits only

i dont get it why 1?

HOLY CRAP! I didn't think I could make an algorithm that could do that!
387427050 serials? Or am I wrong?

This post has been edited by AmuletOfNight: 04 June 2010 - 02:35 PM

### #7 tlhIn`toq

• Xamarin Cert. Dev.

Reputation: 6535
• Posts: 14,450
• Joined: 02-June 10

## Re: How many?

Posted 04 June 2010 - 02:32 PM

In other words
If you are using only digits (0-9) that's 10 possible values for each character.
if you have 5 characters: 10 * 10 * 10 * 10 * 10 = 10^5

If you only use digits 1-9 then you have 9 possible values for each character
9 * 9 * 9 * 9 = 9^5

If you are going to use all letters and all numbers (not considering upper and lower case differently) then you have 36 possible values for each character
36 * 36 * 36 * 36 = 36^5

And so on

• MrCupOfT

Reputation: 2298
• Posts: 9,535
• Joined: 29-May 08

## Re: How many?

Posted 04 June 2010 - 02:32 PM

What does a # symbol represent?
What does a - symbol represent?
What does a X symbol represent?

### #9 AmuletOfNight

Reputation: 3
• Posts: 153
• Joined: 23-July 09

## Re: How many?

Posted 04 June 2010 - 02:34 PM

AdamSpeight2008, on 04 June 2010 - 03:32 PM, said:

What does a # symbol represent?
What does a - symbol represent?
What does a X symbol represent?

# = A number
- = A dash
X = A letter

• MrCupOfT

Reputation: 2298
• Posts: 9,535
• Joined: 29-May 08

## Re: How many?

Posted 04 June 2010 - 02:37 PM

What numbers? And How Many?
What Letters? And How Many?

### #11 raziel_

• Like a lollipop

Reputation: 469
• Posts: 4,281
• Joined: 25-March 09

## Re: How many?

Posted 04 June 2010 - 02:37 PM

now dude look at this tutorial:
http://www.dreaminco...1&#entry1013591

it may give you a start

This post has been edited by NoBrain: 04 June 2010 - 02:37 PM

### #12 AmuletOfNight

Reputation: 3
• Posts: 153
• Joined: 23-July 09

## Re: How many?

Posted 04 June 2010 - 02:38 PM

A number or a letter. It's generating these letters off their name.

### #13 tlhIn`toq

• Xamarin Cert. Dev.

Reputation: 6535
• Posts: 14,450
• Joined: 02-June 10

## Re: How many?

Posted 04 June 2010 - 02:41 PM

#########-XX##

then do the math
9^9 + 26^2 + 9^2

• MrCupOfT

Reputation: 2298
• Posts: 9,535
• Joined: 29-May 08

## Re: How many?

Posted 04 June 2010 - 02:42 PM

So a number I could use -1.28

####-XX##

Where;
# represents a single digit from the set [0-9]
- is just a dash.
X represents a single letter from the set [A-Z]

Combinations = 10^6 * 26^2
Simple to do when have their definitions.

### #15 raziel_

• Like a lollipop

Reputation: 469
• Posts: 4,281
• Joined: 25-March 09

## Re: How many?

Posted 04 June 2010 - 02:42 PM

if you have a capital letters