Two Pointer Linked List Techniques Python

Problems with a normally connected list can be solved by repeating with two pointers. Two Pointers Moving in Parallel

Consider the following problem:

Create a way to return the ninth last element of the same linked list.

To do this, you need some way to know how far you are from the end of the list.

If you wish, you can try your hand at the problem directly, or we can follow some of the approaches below.

Approaches

One thing that comes to mind first is to use this list to store the list representation attached to the list. , And then get the ninth to last element of this list.

The code for this view will look like the following:

def list_nth_last(linked_list, n): linked_list_as_list = [] current_node = linked_list.head while current_node: linked_list_as_list.append(current_node) current_node = current_node.get_next_node() return linked_list_as_list[len(linked_list_as_list) – n]

Instead of creating a complete parallel list, we can solve this problem by using two pointers at different positions in the list but at the same rate.

The side code for this view will look like the following:

nth last pointer = None tail pointer = linked list head count = 0 while tail pointer exists move tail pointer forward if count >= n set nth last pointer to head if it's still None or move it forward increment count return nth last pointer Implementation

Apcsa Casting And Converting

If you are not familiar with the folk tale The Little Glass Slip , a magical entity does magic that changes from a movie costume to a formal costume. Numerical-Based Casting

When we use casting to change the data type of numeric values, it affects the value of the data.

To cast, we need to use the Casting Operator to notify a setter that we want to create a temporary value that has changed The type of data. Narrow Type Casting

double to Example:

double numDouble = 12.99; System.out.println("Double value: " + numDouble); // convert a double to int int numInt = (int) doubleNum; System.out.println("Int value: " + numInt);

The result will be:

Double value: 12.99 Int value: 12

When we have a double to double numDouble = 12.99; System.out.println("Double value: " + numDouble); // convert a double to an int rounded to nearest value int numInt = (int) (doubleNum + 0.5); System.out.println("Int value: " + numInt);

The result will be:

Double value: 12.99 Int value: 13

Sql Common Interview Questions

Congratulations on making it throughout the course!

This article will provide a list of some common SQL interview questions that, along with the answers, you can find in an actual interview.

To get the most out of it, try to answer each question yourself. 1. What is SQL?

MySQL, which means built-in query language, is a programming language for communicating with data stored in relative database management systems.

Its syntax is similar to English, which makes it easier to write, read and translate. 2. What is a database?

A database is a set of data stored in a computer, where the data is structured in such a way that it is easily accessible. 3. What is a relational database?

A relative database is a type of database.

The data in a relative database is often organized as a table.

4. What is a RDBMS?

A relative database management system (RDBMS) is a program that allows you to create, update and manage relative databases.

Most relative database management systems use MySQL language to access databases.

The most popular RDBMS is MySQL. 5. What is a table?

A table is a collection of data divided into rows and columns.

They can contain hundreds, thousands, and sometimes even millions of rows of data.

6. What is a row and column in a table?

A row is the only record of data in a table.

A column is a set of data values ​​of a particular type.

7. What is a data type?

Data type is an attribute that defines the type of data in the column.

Each column in the database has a data type.

Some common data types are INTEGER , A basic key is a column that identifies each row of a table separately.

Primary keys must meet the following requirements: No value can be NULL , no more than one key in each table.

For example, Users In the table, the basic key >>.

A foreign key is the basic key of a table that appears in a different table. 9. What is the difference between ALTER and UPDATE?

ALTER is used to add a new column to the statement table.

Update Used to edit a row in the statement table. 10. What is a query?

A query is a SQL statement used to retrieve information stored in a database.

They allow us to interact with the database by asking questions and returning a result set with the data associated with the query.

11. What is a subquery?

A subfolder is an internal query that resides within an external query.

they select , <<

When a subdomain exists, it will be executed before running an external statement.

12. What are constraints?

Obstacles are a set of rules used to define a database to limit the type of data stored for columns.

They include information about how the column can be used, and are requested after typing data for the column.

Here are some examples of barriers:

Basic key >, which identifies each row individually and the value of each needs to be individualized. 13. What is a statement?

is a statement text that the database recognizes as a valid command.

They can be used to perform tasks such as changing the structure of a table, updating data, or retrieving data from a database.

The structure of a statement may be different, but each should end in a semi-semicolon. 14. How do you check if a field does not have a value or has a value?

When a field has no value, it is indicated by the NULL value.

To test if a field has no value, you can use IS NULL as a condition: WHW

To check if a field has a value, you need to not its status as a condition: DISTINCT A keyword is used when we want to return unique values ​​to the output.

UNIQUE is a barrier used to ensure that all column values ​​are different. 16. What are aggregate functions used for?

Aggregate functions are used to calculate one or more values, and get a value for more meaningful information.

There are some aggregate functions. 17. What is a join?

Adding is a way to combine rows from two or more tables, based on the corresponding columns between them.

18. What is the difference between an INNER JOIN and LEFT JOIN?

A INNER JOIN is used to add common rows from two tables that have 7 indicates.

A left table is used to place all rows from the first table, regardless of whether the << code for the second Whether there is a matching row in the table 19. What is the purpose of windows functions?

Windows functions are used when you want to retain the values ​​of your original table while displaying group or aggregate information. 20. What are indexes and why are they needed?

Indexes are used in the background of a database to speed up the query, acting as a flexible table of databases.

They need to store data efficiently for faster retrieval, which can be critical to the success of large tech companies that execute data on a per-byte byte scale every day. need to.

Dangers Of The Black Box

What Makes Deep Learning Models Dangerous?

When talking about machine learning, deep learning, and artificial intelligence, people focus on the progress and amazing feats we could possibly achieve.

We live in an imperfect world, and the learning algorithms we design are not immune to these shortcomings.

 When to Use Them



<p class = Because of the nature of deep learning models, we should only use them if there is a clear, important reason to use them.

When choosing a solution to a problem, we have to address a number of factors, including

. speed accuracy training time interpretability maintenance enhancement size of the trained model

Before starting the prototype

and much more. Misconceptions

There are often misconceptions about AI and deep learning models and their implications for our world. Key Issues

Here are some key points to explain about machine learning models that can have potentially disturbing implications.

The machine learning algorithm can only be as good as it is trained on

There is also a history of the health industry that does not include enough women and people of color in the medical sciences.

Machine learning models do not understand the effect of a false negative versus false positive diagnostic (at least not like humans) .

Models may not have this “precautionary” attitude, especially if we do not design them with this in mind.

For many physicians and patients, the model is a black box. Stakeholders can only make decisions based on results, and predictions are not open to scrutiny.

a cart More Examples



<p class = For concerns about the use of the learning model in the healthcare industry, this is just the tip of the iceberg, and we have yet to make an impact in other areas as well.

Employing black box technology becomes more of a problem when used without transparency in context.

various & quot & quot Score

Models like these can go beyond mirroring existing inequalities. Personal Responsibility

This is not to say that we should not use machine learning models in ways that affect our daily lives. Interpretability and Transparency



<p class = It is also important that the models we develop are used in ways that are transparent to potential stakeholders. why the model is being used how their personal data is being used what personal data is being used

The last thing to consider is to make the internal workings of your model understandable to your users, also known as interpretive machine learning . In Conclusion

There is no doubt that machine learning can help us create waves of growth.

Dangers Of The Black Box

What Makes Deep Learning Models Dangerous?

When talking about machine learning, deep learning, and artificial intelligence, people focus on the progress and amazing feats we could possibly achieve.

We live in an imperfect world, and the learning algorithms we design are not immune to these shortcomings.

 When to Use Them



<p class = Because of the nature of deep learning models, we should only use them if there is a clear, important reason to use them.

When choosing a solution to a problem, we have to address a number of factors, including

. speed accuracy training time interpretability maintenance enhancement size of the trained model

Before starting the prototype

and much more. Misconceptions

There are often misconceptions about AI and deep learning models and their implications for our world. Key Issues

Here are some key points to explain about machine learning models that can have potentially disturbing implications.

The machine learning algorithm can only be as good as it is trained on

There is also a history of the health industry that does not include enough women and people of color in the medical sciences.

Machine learning models do not understand the effect of a false negative versus false positive diagnostic (at least not like humans) .

Models may not have this “precautionary” attitude, especially if we do not design them with this in mind.

For many physicians and patients, the model is a black box. Stakeholders can only make decisions based on results, and predictions are not open to scrutiny.

a cart More Examples



<p class = For concerns about the use of the learning model in the healthcare industry, this is just the tip of the iceberg, and we have yet to make an impact in other areas as well.

Employing black box technology becomes more of a problem when used without transparency in context.

various & quot & quot Score

Models like these can go beyond mirroring existing inequalities. Personal Responsibility

This is not to say that we should not use machine learning models in ways that affect our daily lives. Interpretability and Transparency



<p class = It is also important that the models we develop are used in ways that are transparent to potential stakeholders. why the model is being used how their personal data is being used what personal data is being used

The last thing to consider is to make the internal workings of your model understandable to your users, also known as interpretive machine learning . In Conclusion

There is no doubt that machine learning can help us create waves of growth.

The Integer And Double Classes

In this article, we will discuss integer and The main purpose of these rapper classes is to exchange ancient data and objects.

Let's look at an example using the array list class.

If you haven't seen the array list class before, you can think of it as a place to save a list of items.

In this example, we are storing numeric data in the entry list.

ArrayList<Integer> myArrayList = new ArrayList<>(); myArrayList.add(5); int num = myArrayList.get(0); // Asking for the first (technically "zero-th") number in myArrayList. num should now hold 5.

This example shows that any How to use the integer wrapper class.

Conversion in rapper classes and thus applies to all types of rapper classes: integer Double 32MWV code "2dMWV" "

This exchange also occurs when starting a rapper class object instance.

Double wrapper1 = 23.456; Integer wrapper2 = 3; Double wrapper3 = new Double(13.57); Integer wrapper4 = new Integer(7); Double wrapper5 = Double.valueOf(30.59); Integer wrapper6 = Integer.valueOf(15);

Each of these instances causes the compiler to autobox the initial value in an object of the correct wrapped class.

Here are some examples where we inbox the values:

// Autoboxing into Integers Integer wrapper = 3; Integer wrapper2 = Integer.valueOf(15); // Unboxing back to ints int primitiveInt = wrapper; int primitiveInt2 = wrapper2.intValue();

As you can see, the easiest way to set inbox or autobox values ​​is to easily assign a rapper object to an old value, or a rapper object to an old variable. Be assigned.

These previous examples also showed some of the methods that exist in rapper classes.

Descriptive Vs Inferential Statistics

Introduction

Explanatory and irrational statistics are two sub-fields of a large field of data. Descriptive Statistics

Descriptive statistics is about summarizing data.

Commonly used descriptive statistics include averages, averages, frequencies, standard deviations and a set of values. Example: Sales Company

Suppose you work for a large company and have been given a sales dataset for the last month. Average # sales per day: 214.0667 % Salespeople that met quota: 60% Total Sales of Each Product This Month: Monthly Sales Throughout the Year:

Data can be interpreted more easily in this format.

Introduction To Corvid

Oops!

Check out our For specific information on enabling and how they work in Corved, our article

Linear Saerch 1 D And 2 D Arrays

Linear search is used to find the value of a target in a list.

title Keep in mind that linear search is great for short lists but not great for dealing with large amounts of data because we search for one item at a time. Are

title Apply Linear Search
Linear Search will start with the first element and check if it matches our target element, and until Search not found The search will continue.

Linear example
The following is the list: [45, 17, 23, -19, 43, 55, 72,

This is the side code for linear search as a method.

for each element in the search_list if element equal target value then print location and return index if element is not found then print message not found and return -1

Let's convert side code to Java!

1D linear search

We have given you liner search class already

What Are Apis Libraries And Packages

You may have heard of the terms API, library and package and wondered what the differences are.

Get started with IPL!

The manuscript “API” is short for the application program interface and is what allows applications to interact with any other piece of software.

An API is actually a description of how to interact with software and the format to use when interacting with it.

An easy way to think about APIs in the context of software libraries is that they contain information about libraries, packages and classes that you can use.

So what is a library?

We’ve learned that APIs describe functionality and interaction with a piece of software, but they don’t contain any code.

Then what is a package?

A package is a group of related classes and interfaces in Java.

! [Diagram connecting these components] (insert image here)

This icon shows the relationship between each component.

Check out what you know about IPIs, libraries and packages!