I do not feel very comfortable with DS & ALGO. I need to know which algorithm / data structure is best for finding file content. I hope most of you have heard of Splunk's logging mechanism these days. I need to understand more about how it seeks delivered value in huge amounts of data in less time.

# Tag: Structures

## Data Structures – How Do You Identify Unlimited Face Given DCEL?

I have a DCEL using the in How do I create a double connected edge list with a series of line segments? Described procedure created.

This will correctly identify all faces. However, I have difficulty finding a way to identify the infinite face surrounding my chart.

So far, my only idea is to find the face polygon that contains all the others by creating a polygonal representation of each face, but this seems somehow chaotic.

## I need table structures that PHPLD uses. To help you

Can somebody release an empty PHP-LD database structure?

I do not need any customer information etc, just the table structure using PHP LD.

You can go to phpmyadmin, click Export,

Leave the "Structure" check box selected and remove the check box from the "Data" area.

and create a dump.

This creates an SQL file with only one structure and no data.

Then please upload it here or just open the file in the editor and paste everything into a comment here.

Thank you very much

## Data Structures – Structure Alias Question

Perform code analysis. How to create the structure alias (and a pointer to the structure):

```
typedef struct _test
{
PULONG_PTR var1;
PULONG_PTR var1;
} test, *ptest;
```

Later in the program, this pointer alias will reappear:

```
Function1(
_In_ *ptest this_is_my_issue
);
```

pay attention to the `this_is_my_issue`

Variable.

Finally, in code, both the pointer alias and the variable I do not understand are used as follows:

```
ptest this_is_my_issue = NULL;
```

My question is:

is `this_is_my_issue`

only the new name of the `ptest`

Value? Maybe I do not offer enough context. I do not really understand how that works `this_is_my_issue`

Variable comes into play.

## Data Structures – Complexity in Finding the 7th Smallest Element in a Min Heap?

I do not know if it's allowed to cross nodes in a min heap.

Because if traversing is allowed, then to find $ 7 ^ {th} $ smallest element, only a constant number of nodes has to be checked, which results in the complexity of $ Theta (1) $,

But if crossing is not allowed, then to find $ 7 ^ {th} $ smallest element, I have to call `extract_min()`

6 times, resulting in a complexity of $ Theta ( log n) $What I think should be right, but not sure.

My understanding is that when I cross, it's not a min heap, it will be an extended min heap. Is it right?

## object-oriented – Representation of mathematical tree structures using software in a compact manner

In my work, I often come across systems of interdependent equations. I invented a toy example as follows. The final values `w`

. `x`

. `y`

and `z`

are given:

`e(y) = A+B`

`A(y) = x*log(y)+y^z`

`B(y) = alpha*y`

`alpha(y) = x*y+w`

We could then look at the function `e(y)`

as the root of an arithmetic tree with the following inheritance:

I used to do something like this in Python to evaluate the result:

```
import numpy as np
def root(B, A):
return B+A
def A(x,y,z):
return x*np.log(y)+y**z
def B(alpha, y):
return alpha*y
def alpha(x,y,w):
return x*y+w
if __name__=='__main__':
x,y,z,w = 1,2,3,4
result = root(B(alpha(x,y,w),y), A(x,y,z))
```

That will give me the right result, but I have come to really despise this way of doing things. I have to track which arguments each function needs and how the tree itself is constructed. Suppose I wanted to change the tree myself by adding branches and leaves. Say, for example, I wanted to redefine `alpha`

as `v+x+y`

with the new variables `v`

, I would have to do a new feature and make a new call, which is not very efficient, as I sometimes have to make ubiquitous and numerous changes.

I've tried different approaches to solving this problem, as outlined in this question and on this issue.

I came across some promising ideas, namely function objects and the interpreter pattern. The interpreter pattern, however, disappointed me. Suppose I did not create a parser and moved directly to the underlying federated architecture. Would not I have to do something like that?

```
root = root_obj(B_obj(alpha_obj(x_obj,y_obj,w_obj),y_obj), A(x_obj,y_obj,z_obj))
root.interpret()
```

The above would require a lot of additional complexity without adding value. My question is this: What is a simple and useful object-oriented paradigm in which I could **define**. **to change** and **assess** a mathematical hierarchy in the most compact way possible?

Thanks for your help.

## Interview – Good Website for Practicing Pure Data Structures

I met LeetCode.com, a great source for practicing interviews. Personally, I think if someone wants to crack an interview in a good technology company, it's a great resource. One thing I've noticed is that it's so much about cracking interviews and solving problems using data structures instead `practicing data-structures`

What I wanted to ask was that there are many problems where data structures are used to solve the problem. What it does not offer, however, is the practice of fundamental changes that particularly improve data structure stills, such as:

- Remove a node from a doubly linked list
- Search a single linked list
- BST

I am looking for a pre-leet code resource that will ensure that I am pre-prepared in basi data structures before attempting to solve problems with Leet code. Any suggestions?

## Data Structures – Where can I find someone to explain the analysis reports from my iPhone and computer?

This may seem like a stupid question to most people, BUT PLEASE READ THIS !! I'm beyond the desperation of getting rid of a hacker who digitally persecutes me and terrorizes me. I chose your forum because there's so much code I see on my phone. This has been like this for over a year and I have only found 1 computer forensics website online. You are a company in Denmark and do not work for consumers, so they would not even help me. The hackers are my ex-roommate and 2 other women who are constantly in our phones. For example, I recently activated Voice Memo on my husband's phone and it showed that the location is a few miles from my actual address. Then I went to my map app on my phone to get directions to a location. It said that I was on a college campus in a completely different city than myself.

I need someone who can read the code and explain to me what the system is and what comes from the hacker. I am obsessed with this problem, which only contributes to the problems caused by the hackers. I go down wormholes (many, MANY) because I have found information on the phone or computer and feel that they are NOT part of the normal operating system functions. Since March of this year, I have no Wi-Fi, no cable, and no data until I turned it on about three weeks ago, because I need it for my job, no debit cards, and no social media. I think they catch the signal at the tower, which is in the middle of a dirt road outside the country. I also believe that I found some of their portals / backdoors / links that they used to get into my devices.

They are relentless, methodical and cruel. You are responsible for 50% of my son's dismissal for faking his number to call and assign the owner of the company and several other employees at 2:00 am.

They track me, all my text messages are routed to someone, my calls are recorded, and they turn on microphones to hear what's going on. They also try to convince me that my husband has an affair. So much has happened in the last year that I can not even remember everyone.

I'm on my knees and ask for help. We can log in remotely or whatever. I have a new job, my dream job, and I can not afford that they have a laptop in the company. It's a new company, so there's no office yet, which means I work from home or the library until we get an office.

I need a profit, please. It's not my tendency to let anyone get away with it. Plus, they're constantly doing things on my phone, like changing my settings, to let me know they're still there.

Thank you for your time and reading. Any advice and / or help is appreciated.

TY

## Data Structures – Forbidden Sequence Dynamic Programming

Given a finite amount $ Omega $I have the following problem. Suppose there is a list of prohibited subsequences $ F subset Omega cup Omega ^ 2 cup Omega ^ 3 dots Omega ^ infty $Although we do not know the contents of the list before, we can query each sequence $ S in Omega ^ i $ to see if $ exists f in F, f subseteq S $, I want to construct a sequence $ S in Omega ^ n $ so that $ f not subseteq S, forall f in F $,

I want to construct all sequences $ S in Omega ^ n $ so that $ f not subset S, forall f in F $,

The approach that I thought best was dynamic programming. We construct iteratively valid sets $ V_k: = {S in Omega_k: f not subset S, forall f in F, | f | <k } $by adding each subsequence of $ s in V_1 cup dots V_ {k-1}, forall s subsetneq S $and then remove all $ S in F $ with queries. My question is how to build most efficiently $ V_k $? A simple way would be to take $ V_ {k-1} $ and then add each element $ Omega $ in the end, and then some additional queries, but is there a better way?

In addition, there are elegant ways to use incomplete valid sentences $ I_k subseteq V_k $where if $ I_ {k + 1}: = {S in Omega ^ {k + 1} setminus F: s in I ^ 1 cup dots I ^ k, forall s subsetneq S } $ Is it empty, can we try to expand everything without having to start from the beginning?

## smooth manifolds – Easier methods for calculating homology / cohomology by adding additional structures

Accept $ X $ is a topological space and I want to talk about his "homology".

There is this notion of singular homology obtained from the singular chain complex. This is not very easy to calculate.

Suppose we assume that there is an additional structure in topological space $ X $So we can talk about the structure of a CW complex and from there to the concept of the cellular chain complex and cellular homology. This is easier than calculating a singular homology.

Let us continue with this topological space $ X $ (which we have assumed to have a CW structure) has an additional structure of a simplicial complex, then we can talk about the concept of the simplicial chain complex and then the concept of simplicial homology. This is easier to calculate than cellular homology.

Then it is the standard result that any two homology groups that come from different approaches coincide, if both are meaningful.

Question: Is there an extra structure (not trivial) that I can add to one?

Space with a simple structure that makes it easier to calculate

Homology in terms of chain complex easier than simple chain

Complex?

The same applies to cohomology. Suppose I have a topological space $ X $I can talk about his singular Cochain Complex and the corresponding singular cohomology.

Suppose this topological space $ X $ Given the structure of a manifold, we can talk about the Cochain complex of differential forms and use it to compute the cohomology of topological space $ X $, It is a standard result that if the coefficients are correct, the singular cohomology is identical to the deRham cohomology (deRham theorem).

Question: Is there an additional structure that I can add to a manifold?

this results in a simpler cochain complex than the cochain complex of

Differential forms that give a simpler way to calculate the cohomology of

the manifold? Suppose I fix a connection on the tangent

bundle up $ TM rightarrow M $ of the distributor $ M $ (or a Riemann metric on the manifold $ M $), I can produce easier

Complex with the compound that calculates cohomology easily?

When I try to find a meaning for the concept of cohomology theory, which connects to the tangent bundle $ TM rightarrow M $ (a metric on the distributor $ M $) then it is to be expected that this concept does not depend on the connection choice that I have defined. Does the assumption that there is a flat connection on the tangent bundle indicate an apparent cochain complex?

Suppose I ask that distributor $ M $ If a Lie group has an additional structure, there is a simpler Cochain complex that computes the cohomology of the manifold more easily than the DeRham cohomology. This is too much to ask, I am looking for results that lie between the deRham cohomology of manifoldness and the strictly lower structure than the notion of Lie groups.

References are welcome.