Samantha was tasked with calculating the average monthly salaries for all employees in the EMPLOYEES table, but did not realize her keyboard's key was broken until after completing the calculation. She wants your help finding the difference between her miscalculation (using salaries with any zeros removed), and the actual average salary. Write a query calculating the amount of error (i.e.: average monthly salaries), and round it up to the next integer.

 SELECT ROUND((AVG(Salary)    -    AVG(CAST(REPLACE(Salary, 0, '') AS int)))+1) FROM Employees;

Mastering JavaScript Array Functions: A Comprehensive Guide

1. `map()`: Transforming Arrays

The `map()` function is used to create a new array by applying a provided function to each element in the original array. It is particularly handy for transforming data without modifying the original array. Here's an example:

const numbers = [1, 2, 3, 4, 5];

const squaredNumbers = numbers.map(x => x * x);

// squaredNumbers will be [1, 4, 9, 16, 25]

2. `filter()`: Filtering Arrays

`filter()` is used to create a new array that contains all elements from the original array that meet a certain condition defined by a provided function. For instance:

const numbers = [1, 2, 3, 4, 5];

const evenNumbers = numbers.filter(x => x % 2 === 0);

// evenNumbers will be [2, 4]

3. `reduce()`: Reducing Arrays

The `reduce()` function is employed to reduce an array into a single value by applying a given function cumulatively to each element. It's quite versatile, allowing you to perform a wide range of operations, such as summing an array of numbers:

const numbers = [1, 2, 3, 4, 5];

const sum = numbers.reduce((accumulator, currentValue) => accumulator + currentValue, 0);

// sum will be 15

4. `forEach()`: Iterating Over Arrays

`forEach()` is used to iterate over an array and perform a function on each element. Unlike `map()`, it doesn't create a new array but is useful for executing side effects or performing actions on array elements:

const fruits = ["apple", "banana", "cherry"];

fruits.forEach(fruit => console.log(fruit));

// This will log each fruit to the console

5. `find()`: Finding Elements

The `find()` function returns the first element in an array that satisfies a provided condition, as defined by a given function. If no element is found, it returns `undefined`:

const people = [

  { name: "Alice", age: 25 },

  { name: "Bob", age: 30 },

  { name: "Charlie", age: 35 }

];

const alice = people.find(person => person.name === "Alice");

// alice will be { name: "Alice", age: 25 }

6. `sort()`: Sorting Arrays

The `sort()` function allows you to sort the elements of an array in place. It can be used with a comparison function for customized sorting:

const fruits = ["apple", "banana", "cherry"];

fruits.sort();

// fruits will be ["apple", "banana", "cherry"]

7. `concat()`: Merging Arrays

`concat()` is used to merge two or more arrays, creating a new array that contains the elements from all the input arrays:

const arr1 = [1, 2];

const arr2 = [3, 4];

const combined = arr1.concat(arr2);

// combined will be [1, 2, 3, 4]

DNA Health Analysis | HackerRank

int formingMagicSquare(vector<vector<int>> s) {

    // Possible magic squares to compare against

    vector<vector<vector<int>>> magic_squares = {

        {{8, 1, 6}, {3, 5, 7}, {4, 9, 2}},

        {{6, 1, 8}, {7, 5, 3}, {2, 9, 4}},

        {{4, 9, 2}, {3, 5, 7}, {8, 1, 6}},

        {{2, 9, 4}, {7, 5, 3}, {6, 1, 8}},

        {{8, 3, 4}, {1, 5, 9}, {6, 7, 2}},

        {{4, 3, 8}, {9, 5, 1}, {2, 7, 6}},

        {{6, 7, 2}, {1, 5, 9}, {8, 3, 4}},

        {{2, 7, 6}, {9, 5, 1}, {4, 3, 8}}

    };

    int min_cost = INT_MAX;

    // For each possible magic square

    for (auto &magic_square : magic_squares) {

        int cost = 0;

        // For each element in the input matrix and the corresponding element in the magic square

        for (int i = 0; i < 3; i++) {

            for (int j = 0; j < 3; j++) {

                cost += abs(s[i][j] - magic_square[i][j]);

            }

        }

        // Update minimum cost

        min_cost = min(min_cost, cost);

    }

    return min_cost;

}

Matrix Layer Rotation | HackerRank | c++

 void matrixRotation(vector<vector<int>> matrix, int r) {

    int m = matrix.size(), n = matrix[0].size();

    int numLayers = min(m, n) / 2;

   

    // Rotate each layer r times

    for (int layer = 0; layer < numLayers; layer++) {

        int layerHeight = m - 2 * layer, layerWidth = n - 2 * layer;

        int numRotations = r % (2 * (layerHeight + layerWidth - 2));

        while (numRotations--) {

            // Rotate right edge

            for (int i = layer; i < layer + layerHeight - 1; i++) {

                swap(matrix[i][n - layer - 1], matrix[i + 1][n - layer - 1]);

            }

            // Rotate bottom edge

            for (int i = n - layer - 1; i > layer; i--) {

                swap(matrix[m - layer - 1][i], matrix[m - layer - 1][i - 1]);

            }

            // Rotate left edge

            for (int i = m - layer - 1; i > layer; i--) {

                swap(matrix[i][layer], matrix[i - 1][layer]);

            }

            // Rotate top edge

            for (int i = layer; i < layer + layerWidth - 2; i++) {

                swap(matrix[layer][i], matrix[layer][i + 1]);

            }

        }

    }

   

    // Print the rotated matrix

    for (int i = 0; i < m; i++) {

        for (int j = 0; j < n; j++) {

            cout << matrix[i][j] << " ";

        }

        cout << endl;

    }

}

The Advantages and Challenges of Full Stack Development: Understanding the Role and Scope of a Full Stack Developer

 

Full stack development is a popular term used in the software industry to refer to developers who have the skills and expertise to work on both front-end and back-end development. A full stack developer can work on the client-side, server-side, and database of an application, and can handle all aspects of the development process from designing and coding to testing and deployment. In this blog post, we will discuss the advantages and challenges of full stack development, and the role and scope of a full stack developer.

Advantages of Full Stack Development

Versatility and Flexibility: 

Full stack developers are versatile and can work on different aspects of a project, which makes them valuable assets to any development team. They can handle all stages of the development process, from designing and coding to testing and deployment, and can adapt to changing project requirements and technologies.

Cost-Effective: 

Hiring a full stack developer can be more cost-effective than hiring separate front-end and back-end developers. With a full stack developer, you can have one person handling all aspects of the project, which can save time and money in the long run.

Holistic View of the Application: 

Full stack developers have a holistic view of the application and can ensure that all components work seamlessly together. This can lead to a more efficient and effective development process, as well as a better user experience for the end-user.

Challenges of Full Stack Development

Constant Learning: 

Full stack development requires a lot of skills and knowledge across multiple domains, which means that full stack developers need to constantly update their skills and stay up-to-date with new technologies and trends.

Limited Expertise: 

Full stack developers may have limited expertise in certain areas, such as design or database administration, which can lead to suboptimal performance in those areas

 

How to install node.js in Windows Machine

Node.js is a popular open-source JavaScript runtime that allows developers to build server-side applications using JavaScript. In this blog post, we will go through a step-by-step guide on how to install Node.js on a Windows machine.

Step 1: Download Node.js Installer

The first step in installing Node.js on your Windows machine is to download the installer from the official website nodejs.org. You can go to the website and download the LTS version.

Step 2: Run the Installer

Once the installer has finished downloading, double-click on the installer file to run it. The installer will guide you through the installation process. You can select the "Next" button to proceed through the installation steps.

Step 3: Accept License Agreement

When you run the installer, you will be presented with a license agreement. Read through the agreement and select the "I accept the terms in the License Agreement" checkbox if you agree to the terms. Then click on the "Next" button to proceed.

Step 4: Select Destination Folder

The next step in the installation process is to select the destination folder where you want to install Node.js. You can either accept the default location or choose a custom location. Once you have selected the destination folder, click on the "Next" button to proceed.

Step 5: Choose Components

In this step, you can choose which components you want to install. By default, all components are selected. If you want to deselect any components, you can do so by unchecking the checkbox next to the component name. Once you have selected the components you want to install, click on the "Next" button to proceed.

Step 6: Install

After you have selected the components you want to install, click on the "Install" button to start the installation process. The installer will begin installing Node.js on your machine.

Step 7: Complete Installation

Once the installation process is complete, you will see a "Completed" message. Click on the "Finish" button to close the installer.

Step 8: Verify Installation

To verify that Node.js has been installed successfully, open a command prompt and type "node -v". This will display the version of Node.js that has been installed on your machine. If you see the version number, it means that Node.js has been installed successfully.

Conclusion

In this blog post, we went through a step-by-step guide on how to install Node.js on a Windows machine. By following these steps, you should be able to install Node.js without any issues. Once you have installed Node.js, you can start building server-side applications using JavaScript.

 

Duplicated Products | C# | HackerRank

ISet<string> uniqueProducts = new HashSet<string>();

for(int i = 0; i < name.Count; i++)

{

    uniqueProducts.Add(name[i] + " " + price[i] + " " + weight[i]);

}

return name.Count = uniqueProducts.Count;