simulation of how to release an already assigned binary code

Dear All,

Let's assume we want to assign a random binary code to each of our inputs. When a code is assigned to one input, it will be shown unavailable. Then I want to simulate a case when after a certain time, some of the inputs release the code they were assigned and these codes will again be shown as available ones and can be assigned to another inputs if needed. Do you have any hint for this?

[Stephen23]

@Sara Ghayouraneh: what is your question?

[Stephen23]

duplicate:

https://www.mathworks.com/matlabcentral/answers/379324-assigning-codes-to-inputs

[Sara Ghayouraneh]

My question is how to write the code? How to simulate the code to be released and be available to be assigned again?