## How to change the semantic version number by reversing the last major change

I am trying to plan a system that validates the compatibility of different components by comparing their semantic version number, especially the main version number (since it indicates API changes and compatibility with previous versions). I found the following scenario where I couldn't find an exact answer:

Let's say the code is in the version 2.3.5 and I add a new major API change, therefore, I update the version to 3.0.0. However, a few days after the launch, I find that this change does not adapt to the needs of the users, and I reverse this change so that everything that is compatible with the versions 2.x.x it will be compatible again (note that I am not doing a reversion of the version control, but instead return the previous version of the code in a regular confirmation). Now I can't understand if the new version should be 4.0.0 because again I made a major change in the API and the numbers should always be increased, or, because it will be compatible with previous versions again, use 2.4.0.

I see advantages and problems with both solutions. Are there basic rules or best practices for such cases?

## Algorithms – Number of subsets

Given a number n, find all subsets of {1, 2, .. n} with the condition taking 2 elements of a subset, the absolute difference is greater than 1.
I found this problem but I have no idea how to solve it, not even recursive. It can be done with dynamic programming.

Entry: 5
Departure: 12

The subsets are: {1}, {2}, {3}, {4}, {5}, {1.3}, {1.4}, {1.5}, {2.4}, {2 , 5}, {3,5}, {1,3,5}.

## reddit: where can I see the classification of subreddits by number of subscribers that allow to publish new accounts?

I want to see subreddits, incl. NSFW, which allows you to publish accounts created seconds ago.

I am not a computer expert, but is it easy to program? Without a doubt I don't have time for each subreddit, then check every user that has posted to see if it is a new account.

## How to remove the version number from a list of programs in Notepad ++

I want to delete / delete the version number from my list of programs in notepad ++.
How can I do it?

Example:
program 1 5.6.3
program 2 3.2.2
program 3 14.2.9

I want it like this:
Program 1
Program 2
Program 3

## Cryptography: is there necessarily an infinite number of inputs for any given output in a hash encryption function?

This could be a very easy question. Consider the cryptographic hash functions with the usual properties, weak and strong collision resistance and preimage resistance.

For any given output, there are obviously multiple entries. But is that necessarily an infinite number of pre-images, for any given hash value?

How would you give a formal proof that there is no hash h () encryption function such that there is a given value v = h (m *) for which the possible set of inputs m * is finite? Would this necessarily break the resistance to collision?

## Age system: what is the target number when it does not have a relevant focus?

How much does the target number go up if a PC does not have a relevant approach? The rules mention that GM decides if they are allowed to roll, but does not mention the target number.

The example in the book (p102) has Miller investigating a martial arts dojo:

• If he has the Primary focus of Communication (Persuasion), the TN is standard. Let's say it's a TN of 11.
• If he doesn't have the main focus, but he has a tangential approach, such as Communication (Negotiation) or Communication (deception) or Fight (Fight), then the TN is +2. That makes the TN 13.
• If he has the Improvisation Talent (p53) you can do things as if you always had the tangential approach, then TN 13 again.

Is the TN still 13 years old if it does not have tangential approaches (foci) and does not have improvisation?

## Age system: what is the target number when it does not have a relevant focus? (Extension)

How much does the target number go up if a PC does not have a relevant approach? The rules mention that GM decides if they are allowed to roll, but does not mention the target number.

The example in the book (p102) has Miller investigating a martial arts dojo:

• If he has the Primary focus of Communication (Persuasion), the TN is standard. Let's say it's a TN of 11.
• If he doesn't have the main focus, but he has a tangential approach, such as Communication (Negotiation) or Communication (deception) or Fight (Fight), then the TN is +2. That makes the TN 13.
• If he has the Improvisation Talent (p53) you can do things as if you always had the tangential approach, then TN 13 again.

Is the TN still 13 years old if it does not have tangential approaches (foci) and does not have improvisation?

## cv.complex variables – Another type of imaginary number

The imaginary number $$i$$ ($$i ^ 2 = -1$$) has proven not only to be a source of many theoretical mathematics, but also to be useful in science and engineering. Another type of imaginary number is $$j$$ (the number whose logarithm is -1: $$e ^ j = -1$$); Have the mathematics of this concept been explored? The concept of a complex number, $$a + jb$$or $$e ^ a + jb}$$Does it make sense in this context?

## google sheets: how do I count the number of cells that are not blank in a row, including only the cells that are in a column that contains a specific value?

Here is my sample sheet:

I am trying to create a formula for the "Total" column that would contain the total number of non-blank cells for that row, counting only the cells that are in a column that contains the value "B". (0 count as not blank)

Finding the sum of these columns is quite easy, using this formula (for row 2 as an example):
=SUMIF($1:$1,"B",2:2)

However, to count cells that are not blank, I couldn't find a similar way to do it. I tried to address this using FILTER Y COUNTIF, but I couldn't understand it.

## test writing – Let p be a prime number greater than or equal to 3. Prove that if p ≡ 1 (mod 3), then p ≡ 1 (mod 6).

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