Notes, summaries, assignments, exams, and exercises for Computer science for University

Information Technology Fundamentals

Information Technologies: These are the tools and methods used to collect, store, handle, or distribute information.

Hardware: This includes any physical component of technology that works or somehow interacts with the computer.

Characteristics of the Third Generation of Computers

• Integrated Circuit Chips: These chips comprise thousands of transistors on a silicon wafer.
• Performance: They offer increased processing speed and improved existing storage systems.
• New Programming Languages: Introduction of Pascal, BASIC, and Logo.

Software: This refers to all the intangible components of the computer; it is a group of programs.

RAM (Random Access Memory): This temporarily stores data and instructions; it is measured in...

Relational Databases (BDR)

Relational databases (BDR) are a collection of tables with unique names, which may be related to one or more other tables. Concepts such as referential integrity and primary keys ensure that a value referenced in one table is present in the table being referenced, and that a set of information can be represented consistently and accessed independently.

Object-Oriented Databases (BDOO)

Object-oriented databases (BDOO) have three main pillars: inheritance, polymorphism and encapsulation. This model offers greater flexibility in manipulation and a richer content structure, and objects can be handled consistently.

Conventional Databases vs. New Application Requirements

Conventional database systems feature uniformity among...

Open Systems Architecture

This definition refers to computer systems architecture that enables interconnection and easy distribution.

Key Features

• Not tied to a single type of proprietary hardware.
• Integrated information environment.
• Meets and/or generates standards.
• General specifications.
• High degree of software portability.
• Flexibility of programming languages.
• Management of different operating environments.

Data Packets

The data packet contains the source address, where it generates the packet, and the destination address.

Transmission Medium

A medium is the material through which data travels. It can be any of the following materials:

• Telephone cables
• UTP coaxial cable
• Fiber optic

Communication Protocols

A set of rules, or an agreement, which determines...

Linux System Administration Knowledge Check

I. Processes and System Management Fundamentals

1. The processes are: F.
2. An orphan process: V.
3. The Kill Command: F.
4. The top command: V.
5. For information: V.

II. File System, Commands, and Permissions

Any information or documents: F. The dir command: F. Hidden files: V. If in a line: V. The command ls /etc/f*: V. The /etc/fstab file: F. Even though we have: F. Using the grep command: F. cp -i: F. The mv -r command: F. bzip2: F. To decompress: V. The command passwd: F. To list the contents: F. To mount a directory: F. ln /home/pepe/public: F. The command who: V. The command line root@: F. chmod g+x: F.

III. Networking and Connectivity Configuration

wget -r: V. Network interfaces: V. Any user: F. No user: F. Get...

Custom POSIX Barrier Implementation

This structure defines a custom barrier for thread synchronization:

typedef struct {
    int total;          // Expected threads
    int count;          // Arrived threads
    int phase;          // Current phase (for reuse)
    pthread_mutex_t mutex;
    pthread_cond_t  cond;
} barrier_t;

Barrier Initialization and Destruction

• Init: Sets the total thread count and initializes synchronization primitives.
• Destroy: Cleans up mutex and condition variables.

Barrier Wait Logic

The barrier_wait function ensures all threads reach the synchronization point before proceeding, utilizing a phase-based approach to allow barrier reuse.

MPI Vector Types for Chessboard Patterns

Using MPI_Type_vector to handle non-contiguous memory...

Chapter 1: Program Generation and Execution

The compilation process consists of 4 steps:

1. Preprocessing: Input a .c file, output a .i file. It expands all macro definitions, processes #include (inserts header file contents), handles conditional compilation directives such as #ifdef, and removes comments.
2. Compilation: Input a .i file, output a .s file (assembly code). It translates C into assembly language, performing syntax analysis, semantic analysis, and optimization.
3. Assembly: Input a .s file, output a .o file (relocatable object file). It translates assembly language into machine code (binary), but addresses are not yet determined.
4. Linking: Input multiple .o files and library files, output an executable file. It performs symbol resolution (associating

...

Addition of Two Numbers

<?php
if(isset($_POST['n1']) && isset($_POST['n2'])){
    $n1 = $_POST['n1'];
    $n2 = $_POST['n2'];
    $res = $n1 + $n2;
    echo "<h3>User Input Numbers:</h3>";
    echo "First Number = $n1 <br>";
    echo "Second Number = $n2 <br>";
    echo "Sum = $res";
}
?>

Enter Two Numbers:

PHP Conditional, Loops and Arrays Example

<?php
echo "<h3>Loop Example (1 to 5):</h3>";
for($i=1;$i<=5;$i++){
    echo "Number: $i <br>";
}
echo "<h3>Array Example:</h3>";
$fruits = array("Apple","Banana","Mango","Orange");
foreach($fruits as $f){
    echo "$f<br>";
}
?>

Student Registration Form

Name:

Email:

Gender:
Male
Female

Subjects:
Math
Science
English

Course:

...

C++ Pointer and Array Operations

This collection demonstrates fundamental C++ techniques for handling pointers, arrays, and memory management.

Core Functions

void squareByPointer(int* n) { 
    *n = (*n) * (*n);
}

void capitalizeFirst(char* word) { 
    word[0] = toupper(word[0]);
}

void fillWithSquares(int* arr, int size) {
    for (int i = 0; i < size; i++)
        arr[i] = i * i;
}

int sumArray(const int* arr, int size) {
    int sum = 0;
    for (int i = 0; i < size; i++)
        sum += arr[i];
    return sum;
}

void swap(int& a, int& b) {
    int temp = a;
    a = b;
    b = temp;
}

int* makeFilledArray(int size, int val) {
    int* arr = new int[size];
    for (int i = 0; i < size; i++)
        arr[i] = val;
    return

...

JavaFX Calculator Implementation

This implementation defines a desktop calculator application built using JavaFX, utilizing a BorderPane and GridPane to manage the user interface components.

Complete JavaFX Source Code

import javafx.application.*;
import javafx.stage.*;
import javafx.event.*;
import javafx.scene.*;
import javafx.scene.control.*;
import javafx.scene.layout.*;
import javafx.scene.input.*;
import javafx.scene.paint.Color;

public class Main extends Application {
    int operation = -1;
    double data = 0;
    private TextField Resultado;

    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("Calculadora");
        Group G = new Group();

...

Jabber JID to Email Conversion

def jid2email(jid):
    email = jid[:jid.find('/')]
    return email

if __name__ == '__main__':
    jabber = '[email protected]/quertyy'
    print(jid2email(jabber))

Lists vs. Tuples

Lists are mutable and can be changed by internal operations, whereas tuples are immutable.

Remove Duplicates from String

def remove_dup(string):
    result = []
    for char in string:
        if char not in result:
            result.append(char)
    return ''.join(result)

Identical Character Count

def count_max(in_string):
    d = dict()
    for c in in_string:
        d[c] = d.get(c, 0) + 1
    return max(d.items(), key=lambda x: x[1])

# Using collections
from collections import Counter
def counter_max(in_string):
    return Counter(in_

...