Map from fixed length string to a unique number

Question

I'm looking for an algorithm (or hash, etc...) that can map a fixed length string (15 character) to unique number (5 digits). I expect it to map ABCDEFGHIJKLMNO to 12450 or ONMLKJIHGFEDCBA to 15647 (The generated number must be unique).

Just do a 16bit CRC, pad it with 0's or something, https://stackoverflow.com/questions/22860356/how-to-generate-a-crc-16-from-c-sharp — TheGeneral, Jun 17 '19 at 06:38

fubo · Answer 1 · 2019-06-17T06:35:34.283

3

it's not possible to map

a fixed length string (15 character)

into a

unique number (5 digits)

because 15 characters with 26 possible characters (A-Z) > than 5 digits with 10 possible digits (0-9)

so 26^15 > 10^5 or 1.677.259.342.285.725.925.376 > 100.000

edited Jun 17 '19 at 06:35

answered Jun 17 '19 at 06:30

fubo

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score 1 · Answer 2 · answered Jun 17 '19 at 06:31

1

What you are asking for is impossible.

There are more possible 15 character strings than there are possible 5 digit numbers. Therefore it is impossible to map each string to a unique number.

answered Jun 17 '19 at 06:31

Greg

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score 0 · Answer 3 · answered Jun 17 '19 at 07:03

0

It is truly impossible to do that. Unless, if you change it into alphanumeric, maybe that could work.

answered Jun 17 '19 at 07:03

Syafiqur__

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Map from fixed length string to a unique number

3 Answers3