Notes, summaries, assignments, exams, and problems for Computers

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Structural and Behavioral Design Patterns in Software Development

Classified in Computers

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Structural Design Patterns

Decorator - Adds additional functionality to a class

Adapter - 'adapts' one interface for a class into one that the client expects

Façade - creates a simplified interface from an existing one

Flyweight - A high quantity of objects share common properties to save space.

Bridge - decouples an abstraction from its implementation so that the two can vary independently.

Behavioral Design Patterns

Chain of Responsibility - Linked list of handlers

Command - Enables all the info for a request to be contained within a single object.

Interpreter - Developing domain specific languages

Iterator - Sequentially access elements of an aggregate object.

Mediator - Removes the need for classes to communicate with each other directly.

Observer... Continue reading "Structural and Behavioral Design Patterns in Software Development" »

Data Project Management: A Comprehensive Guide to DR, MVP, and Data Pipelines

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Data Project Management: A Comprehensive Guide

Goal Setting: The Foundation of Project Planning

Every project requires a clear destination to determine its success. Goal setting is the first step in project planning, providing a roadmap for the project's journey.

Tools & Skills: Assessing Project Resources

The upper blocks of DR (Data Requirements) focus on evaluating the resources necessary for data project implementation. These resources include:

  • Hard Resources: Data, software tools, processing
  • Soft Resources: Skills, domain expertise, human resources for execution

Process & Value: Implementation and Delivery

The lower blocks of DR concentrate on project implementation and delivery. DR serves as a planning tool, helping project managers:

  • Identify
... Continue reading "Data Project Management: A Comprehensive Guide to DR, MVP, and Data Pipelines" »

Embed and Link Objects in Presentations: Best Practices

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Inserting Tables into Slides

In the Insert Object dialog box, click the Create From File option and click Browse to locate and choose the document or spreadsheet that contains the table. By default, the presentation software will insert the table. When you click OK, the entire document or spreadsheet is imported to your slide. Double-click the inserted text to remove extra text if the document contains more than the table. If you check the Link checkbox while inserting, after you update the table in the document or spreadsheet, then right click on the imported table in the presentation software, and select the option Update Link, the embedded table gets updated automatically. Drag and drop the table on the slide to position it.

Chart Design Principles

Convey... Continue reading "Embed and Link Objects in Presentations: Best Practices" »

Java Programming Concepts and Functions

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public static void main(String[] args) {
Scanner entrada = new Scanner(System.in);
String frase= entrada.nextLine();
Stack invertidas = new Stack();
Queue ordenadas = new LinkedList();
for(int i=0;i char letra= frase.charAt(i);
if(Character.isLetter(letra)){
invertidas.push(Character.toLowerCase(letra));
ordenadas.add(Character.toLowerCase(letra));
}
}
while(!invertidas.isEmpty() && invertidas.peek()==ordenadas.peek()) {
invertidas.pop();
ordenadas.poll();
}
if(invertidas.isEmpty() && ordenadas.isEmpty()){
System.out.println( 'A frase é palíndrome');
}
else{
... Continue reading "Java Programming Concepts and Functions" »

Understanding Time Complexity in Sorting Algorithms

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1. What is recurrence for worst case of QuickSort and what is the time complexity in Worst case? Recurrence is T(n) = T(n-1) + O(n) and time complexity is O(n^2) 2. Suppose we have a O(n) time algorithm that finds median of an unsorted array. Now consider a QuickSort implementation where we first find median using the above algorithm, then use median as pivot. What will be the worst case time complexity of this modified QuickSort. O(nLogn)  3. Given an unsorted array. The array has this property that every element in array is at most k distance from its position in sorted array where k is a positive integer smaller than size of array. Which sorting algorithm can be easily modified for sorting this array and what is the obtainable time complexity?

... Continue reading "Understanding Time Complexity in Sorting Algorithms" »

Excel Pivot Tables, Search and Logic Functions, Macros

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Explanation

10.1 Pivot tables

What is a pivot table? It is one of the most powerful tools in Excel. They are also called “dynamic” because the data on them can be changed by rearranging or changing the position of the column and row headers in an easy and quick way.

The use of a dynamic table is to obtain information summaries from our data grid in order to be able to quickly analyze big volumes of information. These type of tables can be used in situations such as:

  • When you have a table with rows that have different date and you need to organize the information by time periods (month, semester, etc.)
  • When you need to change the arrangement in the rows or column cells to show different perspectives from the same data set.


Follow these steps to... Continue reading "Excel Pivot Tables, Search and Logic Functions, Macros" »

Telecom Standards: Business Values, Bodies, and Acronyms

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Business Values of Telecom Standardization for Operators

  1. Multiple sources of supply (decrease risk of sole supplier dependencies/lock-in, improve choice at competitive prices).
  2. Interoperability, e.g., multi-vendor networks, service interop.
  3. Assurance that investment in technology should not abruptly change or fail.

Business Values of Telecom Standardization for Vendors

  1. Network vendors can sell to all service operators, freed from vendor-specific R&D.
  2. Reduce customization.
  3. Build reputation / customer confidence - strong standards brand.
  4. Larger markets from wide adoption, greater economies of scale.

Types of Standards Bodies

  1. Accredited
  2. Treaty-based
  3. Partnerships

Telecom Acronyms Explained

  1. ITU: International Telecommunication Union
  2. IETF: Internet Engineering
... Continue reading "Telecom Standards: Business Values, Bodies, and Acronyms" »

SQL*Plus and Oracle Database: Test Questions and Answers

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SQL*Plus is the version of SQL used to access Oracle databases

1.True

2.False

SQL*Plus del command can delete all lines from the buffer at once

1.True

2.False

There is no difference between the CHAR and VARCHAR2 data types. They are just spelled differently

1.True

2.False

Which command(s) set the title of SQL*Plus report

  1. Set Headsep
  2. Column
  3. Set PageSize
  4. Set Line Size
  5. Edit
  6. Define_Editor
  7. Start
  8. Remark
  9. /* */
  10. Host
  11. Ttitle
  12. Btitile
  13. @
  14. Break On
  15. Compute Sum
  16. Set NewPage
  17. Set Pause
  18. Save
  19. Host
  20. Command is not in the list
  21. Command does not exist

Table in Oracle cannot be created if the primary key is not specified

1.True

2.False

Alternate key may contain NULL values

1.True

2.False

Table can have several alternate keys, but only one primary key and one foreign key

1.True

2.False

Which command(s) is/... Continue reading "SQL*Plus and Oracle Database: Test Questions and Answers" »

SQL Aggregate Functions: COUNT, SUM, MIN, MAX, AVG

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Aggregations

Consider the case of sports tournaments like cricket. Players' performances are analyzed based on their batting average, the maximum number of sixes hit, the lowest score in a tournament, etc.

In such scenarios, we perform aggregations to combine multiple values into a single value, i.e., individual scores into an average score.

Let's learn more about aggregations to perform insightful analysis using the following database.

Database: The database consists of a player_match_details table that stores information about players' details in a match, such as name, match, score, year, and the number of fours and sixes scored.

Schema

12345678
player_match_details (name VARCHAR(250),match VARCHAR(10),score INTEGER,fours INTEGER,sixes INTEGER,year
... Continue reading "SQL Aggregate Functions: COUNT, SUM, MIN, MAX, AVG" »

Python Class: Store Management System

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Python Store Management System

This code defines a Store class in Python, designed to manage customers, sellers, and orders. It uses basic object-oriented principles and data structures.

Class Definition

from Problema2.Cliente import Cliente
from Problema2.Vendedor import Vendedor

class Tienda():
    def __init__(self):
        self.__personas = []
        self.__pedidos = []

    def altaCliente(self, Cliente):
        alta = False
        if Cliente in self.__personas:
            alta = False
        else:
            self.__personas.append(Cliente)
            alta = True
        return alta

    def altaVendedor(self, Vendedor):
        alta = False
        if Vendedor in self.__personas:
            alta = False
        else:
... Continue reading "Python Class: Store Management System" »