## data structures – Given a binary min-heap, find the \$k\$-th element

data structures – Given a binary min-heap, find the \$k\$-th element – Computer Science Stack Exchange

## probability – Using inclusion-exclusion principle to find the pribabilty of events

One draws objects $$A_i$$ that contain each 1 of 5 figures ($$F_1, F_2,…F_5$$) with an equal probability of $$1/5$$ . Using the inclusion-exclusion principle, I have to determine the probability to find the figures $$F_1, F_2, F_3$$, while picking at random 6 such objects.

In the case of 3 events, the exclusion-inclusion principle is: $$P(A_1cup A_2cup A_3)=P(A_1)+P(A_2)+P(A_3)-P(A_1cap A_2)-P(A_1cap A_3)-P(A_2cap A_3)+P(A_1 cap A_2 cap A_3)$$

In the case of 6 events, the formula gets very complicated. The other problem is the difficulty for me to formalize the given problem in probabilistic terms by means of the inclusion-exclusion principle.

Can you provide some hint ? Thanks.

## recover private key – is there a way to find the wallet that my address goes to ?//

I two years ago had a cash out from a casino and i went to myapp store and downloaded what I was coinbase wallet which it was the cold storage wallet that really has no ties beside a wallet connect to coinbase I later figured out. I was brand new to btc and knew nothing about 12 words that i was to immediately write down. I did make an account at wallet.coinbase.com/kristymoser2018 is what I thought was it. I later on saw the money come into my wallet from the casino and at that point it shut my phone down and erased eveything.. when I came back online I found out that I no longer had an account at wallet under the credentials I thought were right

I guess what I am asking is there any other way to figure out where the wallet is cause it still has the money in it and is there any program I can use that may help me figure out where it is and if my private key is in cloud storage?

I have tried to recreate the same scenarfio and have never been ABLE TO understand this

## bitcoin core – How difficult is it to find a hash digest beginning with at least twelve zeros?

How difficult is it to find a hash digest beginning with at least twelve zeros?

what i know is Difficulty is a measure of how difficult it is to find a hash below a given target.

The Bitcoin network has a global block difficulty. Valid blocks must have a hash below this target. Mining pools also have a pool-specific share difficulty setting a lower limit for shares.

and difficulty = difficulty_1_target / current_target

(target is a 256 bit number)

difficulty_1_target can be different for various ways to measure difficulty. Traditionally, it represents a hash where the leading 32 bits are zero and the rest are one (this is known as “pool difficulty” or “pdiff”). The Bitcoin protocol represents targets as a custom floating point type with limited precision; as a result, Bitcoin clients often approximate difficulty based on this (this is known as “bdiff”).

but can someone explain me how difficult is with 12 zeros?

## mathematics – Given its direction, and another vector that begins at the same point, how can I find the magnitude of that vector using only vector math?

Fundamentally, you have a right-angle triangle

Your vector `a` is (conveniently) the adjacent side

You want to know the length of the hypotenuse which is coincident with `b`.

`θ` is the angle between your two vectors which we can get by calculating their dot product.

So I can’t see any simpler option than

``````magnitude(a)/cos(dot(a, b))
``````

Note that in your question, you alternate which vector is extended and which is attached to a right-angle. The above assumes you know `a` and want to find the magnitude of `b`.

## virtualbox – Why can’t VMware Workstation Player find the Guest Windows OS?

I want to use VMware Workstation Player (VWP) to run Windows10 as a guest on a 20.04 host. (Virtualbox does not do well.)

Following VMware directions:

1. I exported the Virtualbox Windows10 vdi (freshly updated), to an “.ova” file. I used the default settings.
2. I then imported that file into VWP. (Note that it took the “retry” that must be common; as the ova file does not meet all of the standards for such files.)

When trying to start the machine, I get a message that Sata0 can not be found. Then I am told that no OS is found.

Why is Sata0 not found? (The HD on which the host lives?)
Why is an OS not found? (The vdi was just used in virtualbox.)

I ask this forum, because I followed the VMware directions, to no avail.

Thanks,
Tim

## Why can I not find my Youtube channel when searching by it’s new name?

I had a youtube channel called `Alhaitham Corp` with `Alhaitham` as first name and `Corp` as last name. Yesterday, I changed the name to an Arabic name `الهيثم للبرمجيات` with `الهيثم` as first name and `للبرمجيات` as the last name. The name was changed successfully and anyone can see the new name. When I search for it on Youtube with the old name, I find it as the first one in the result set. But when searching with the new name, I do not find it at all. So, what I am saying is that the name changing process took effect in all places but users can not use the new name to search for the channel.

## Find a pair \$p,q\$ of polynomials for which \$p\$ \$circ\$ \$q\$ = \$q\$ \$circ\$ \$p\$.

Can anybody tell me what does the notation $$circ$$ mean in the below question ?$$\$$
Find a pair $$p,q$$ of polynomials for which
$$p$$ $$circ$$ $$q$$ = $$q$$ $$circ$$ $$p$$.

## Usando C++ Code::Blocks + SDL2. Erro de cannot find -lsfml-graphics-s-d, -lsfml-window-s-d,

Aparece essa mensagem, como posso resolver isso?

cannot find -lsfml-graphics-s-d

cannot find -lsfml-window-s-d

cannot find -lsfml-system-s-d

cannot find -lsfml-audio-s-d

cannot find -lsfml-network-s-d

cannot find -lsndfile

cannot find -lopenal32

cannot find -ljpeg

cannot find -lglew

cannot find -lfreetype

Já coloquei a pasta ” include ” na opção ” Project Build Options: 1° Opção, sem ser a debug ou release, Search directories > Compiler ” e a ” lib ” na ” Search directories > Linker ” e os arquivos da pasta ” bin ” na minha pasta do meu projeto. Que são: SDL2.dll e sdl2-config.

OBS: Estou começando e não entendo muito do assunto.