Юрий Топчий Юрий Топчий - 8 months ago 61
PHP Question

Generating unique integer I'd from two integer id's

Help, please!

Given 2 integers a and b (positive). Is there any formula / method for generating unique ID number?

note: result from f(a,b) and f(b,a) should be the same. And this solution should work fast with large amount of data. No matter it would be a scratch of PHP code or algorithm.

Thank you!

Answer Source

Example for 32-bit numbers (using left shift)

Int64Code = Max(a, b) + (Min(a, b) << 32)