## One-way function is not injective when it is in NP

Let us $$\Sigma = \{0,1\}$$ and $$f: \Sigma^* \rightarrow \Sigma^* \in FP$$ for which is valid that $$\exists k: \forall x \in \Sigma^* : \lvert x \rvert ^ {1/k} \leq \lvert f(x) \rvert \leq \lvert x \rvert ^ k$$. Thus, we can say that the function $$f$$ is one-way function.

We have language $$L = \{ w \; | \; \exists z \in \Sigma^*, w = f(z)\}$$. The question is, how to prove that $$f$$ is not injective if $$L \in NP \setminus UP$$, where $$UP$$ is the class of unambiguous TM.

It is clear, that if $$L \in NP \setminus UP$$ then exists NTM which decides this language and may exist at least one acceptable path for $$w \in L$$.

## Is the Warlock’s Awakened Mind telepathy two-way, or only one-way?

When warlock chooses a pact with The Great Old One, he gains a feature called Awakened Mind:

Starting at 1st level, your alien knowledge gives you the ability to touch the minds of other creatures. You can communicate telepathically with any creature you can see within 30 feet of you.

My question is, is the communication two-ways, or only one-way?

I assume it’s only one-way: I can “send” messages to target creature’s mind but I can’t receive any responses. So it’s not possible for this creature to “send” me back any thoughts or messages and I can’t read any of the creature’s thoughts.

## One-way Trapdoor Function

Do the functions of the collatz conjecture and their inverses model a Trapdoor Function?

That is, given f(n) = n/2 or 3n+1 and the inverse g(n)=2n and (n-1)/3 it is easy to go from 42 to 1 by repeating the steps but it requires a nondeterministic Turing machine to find g(42).

## Is the ability to telepathically communicate with a Familiar only one-way?

The most recent PHB errata clarified that the Steed generated by Find Steed can communicate telepathically with its summoner.

In the next-to-last paragraph, “communicate with it” is now “communicate with each other.”

However, there was no corresponding change in the text of Find Familiar, which still states that the summoner can “communicate with it.” Does this lack of similar change indicate that the telepathic communication with Find Familiar is one-way?

## One-way functions [on hold]

I would like to know the current state of the art on proving the existence of one way function and in particular the most recent results and the best candidates to fill this role. In particular I would like to know which papers and articles to read to keep me updated on the most recent developments. Thank you.

## Is it possible to split a return flight into two one-way tickets?

My Indian friend has been issued a six month UK visitors visa and has booked a return trip (Delhi – Manchester) in November. I have just booked a one-way ticket for him in July with a different airline. Can he split his November booking so as to use the return leg as proof of return for the July trip?

## cache Hit rate and miss rate calculation one-way associative

I have this problem:
A program that calculates the sum of 128×128 matrix of 32-bit integers (by rows). I have one-way cache that has 8 sets with block size of 64 bytes, considering only the access to the matrix not the instruction.
I should calculate its miss rate.
And also the miss rate by reading the matrix by column. Sorry if there are grammar mistakes, I only translated it to English.

What I’ve done so far is that (correct me if I’m wrong):

• Integer size = 4B
• 64/4 = 16 (integers inside a block)
• 128/16 = 8 (blocks per row)
• 16 hit and 1 miss (each block)
• 128 hit and 8 miss (each row)
• 1024 hit and 64 miss (all the matrix)
• miss rate = 64/1088 = 0.06 = 6%

## Strong Consistency using one-way communication in microservices [on hold]

So to cut a long story short I’ve read multiple articles that highlight the fact that in order to reduce coupling between micro services one should prefer one-way communication instead of synchronous communication (request/response or request/reply).

That being said I know have a dilemma, how could I achieve strong consistency or feedback inside one of my consumers when the communication is one way, this is best explained through an example

• Account Service – Responsible for Balance & Monetary Transactions
• Auction Service – Responsible for auctioning and securing monetary transaction for online auction taking place.

So the user story goes something like this; 1. Item is put for Auction 2. Auction Starts 3. Customer place bid but in order to place the bid the system needs to validate that the player has enough money to secure the item. (Assumption Clients are able to have parallel Auctions going on simultaneously) 4. Customer get outbid the locked funds get released 5. Customer wins the auction the locked funds are transferred to the owners account

How would you be able to implement a consistent system which would not allow a client to place a bid unless he has reserved the monetary amount before hand using one way communication?

## One-way train from Paris to Barcelona

I’m traveling with my fiance this summer (early August) for 10 days, five in Paris and five in Barcelona. We already have flights and hotels set up, and wanted to take the train from Paris (early afternoon) to Barcelona (arriving that evening). However, depending on the website I’ve seen prices range across hundreds of dollars, and I’ve seen plane tickets go for less than some of the train tickets.

Cost isn’t a huge issue, but we don’t want to spend hundreds (USD) per ticket. We will have about two bags per-person, one larger suitcase and one personal bag. This is the first time either of us have taken an international train in Europe so we’re hitting the same wall in terms of understanding and decision making. Thank you!

Edit: My primary concern is that some train ticket websites have mentioned passes specifically for international train travel that would be a separate purchase. We do not currently have any such passes, and were only looking at train tickets. Are there additional documents required for this trip, other than our passports and the train tickets?

## Can you book a one-way ticket to the UK on a visa?

My mother in law has a 2 year visa for the UK. She is planning to visit her family in the UK from Turkey on a 1 way ticket. Is this possible? She would like to decide once she is here in the UK when she would like to return, obviously within the the 2 year visa time limit. It is also cheaper doing it this way.