Top 10 Algorithms for Competitive Programming

A very happy new year 2020!
As I enter the final year of my MCA programme, I would like to share the following link which is very useful for Competitive Programming and programming is general.

https://www.geeksforgeeks.org/top-algorithms-and-data-structures-for-competitive-programming/#algo1

NAT: network address translation and it's 4 types

Link to NAT and it's types including port forwarding.

PKI: public key infrastructure and CAs

Great link to a video on PKI

Kerberos: The user authentication method using 3 secret keys

A great link to the Kerberos method.

Worm code in Python

https://github.com/keniel123/Worm

PDF: probability density function

https://en.m.wikipedia.org/wiki/Probability_density_function

Decision Surface/Boundary problem in Statistical Classification

https://en.m.wikipedia.org/wiki/Decision_boundary

In machine learning and statistics, classification is the problem of identifying to which of a set of categories (sub-populations) a new observation belongs, on the basis of a training set of data containing observations (or instances) whose category membership is known. Examples are assigning a given email to the "spam" or "non-spam" class, and assigning a diagnosis to a given patient based on observed characteristics of the patient (sex, blood pressure, presence or absence of certain symptoms, etc.). Classification is an example of pattern recognition.

In the terminology of machine learning,^[1]classification is considered an instance of supervised learning, i.e., learning where a training set of correctly identified observations is available. The corresponding unsupervised procedure is known as clustering, and involves grouping data into categories based on some measure of inherent similarity or distance.

Often, the individual observations are analyzed into a set of quantifiable properties, known variously as explanatory variables or features. These properties may variously be categorical (e.g. "A", "B", "AB" or "O", for blood type), ordinal (e.g. "large", "medium" or "small"), integer-valued (e.g. the number of occurrences of a particular word in an email) or real-valued (e.g. a measurement of blood pressure). Other classifiers work by comparing observations to previous observations by means of a similarity or distance function.

An algorithm that implements classification, especially in a concrete implementation, is known as a classifier. The term "classifier" sometimes also refers to the mathematical function, implemented by a classification algorithm, that maps input data to a category.

Terminology across fields is quite varied. In statistics, where classification is often done with logistic regression or a similar procedure, the properties of observations are termed explanatory variables (or independent variables, regressors, etc.), and the categories to be predicted are known as outcomes, which are considered to be possible values of the dependent variable. In machine learning, the observations are often known as instances, the explanatory variables are termed features (grouped into a feature vector), and the possible categories to be predicted are classes. Other fields may use different terminology: e.g. in community ecology, the term "classification" normally refers to cluster analysis, i.e., a type of unsupervised learning, rather than the supervised learning described in this article.

Relation to other problems

Frequentist procedures

Bayesian procedures

Binary and multiclass classification

Feature vectors

Linear classifiers

Windows 2000 operating system

https://simple.m.wikipedia.org/wiki/Windows_2000

Network PROTOCOLS

Classification of compter networks based on PROTOCOLS used/supported by them

Cash Flow Statement: MCS035 (AFM)

Preparation of SCWC( Statement of Changes in WC a great illustration with explanation by
Kaursewise Tutorials

CFS  great illustration by Kaursewise Tutorials.

Cash Flow Statement  explained in a very simple and effective way by Ruchi Thakkar.
Nice explanation of what you understand by CFS 

Funds Flow Statement preparation : AFM

Funds Flow Statement preparation wonderfully explained by Parwinder Rani

FFS  great explanation & illustration by Kaursewise Tutorials

Depreciation: AFM

What is Depreciation all about depreciation and is features by Tanya Kapil

Depreciation calculations by Tanya Kapil

Accounting Concepts: MCS035 , AFM

All 12 accounting concepts explained by Pradeep jha.

Profit & Loss Account , Accrual basis of accounting

P/L Account preparation excellent explanation by Shudir Sachdeva

GANTT chart

What is a Gantt chart video



GANTT chart using MS Excel

PERT chart

Beautifully explained below by Project manager

Structure Chart: A visual tool for planning our 'source code' in Software Engineering

Superb lecture on Structure chart by Prof. Chakrobarty .

Structure Charts

Context Diagram and Process 0 in a DFD: Software Engineering

Superb video learning sessions by Shally cashman Dfd.

Bellman-Ford Algorithm

Bellman-Ford explained in detail

Workstation Vc PC

Workstation Vs PC Vs Gaming station

Manchester Encoding: Digital to Digital Encoding

Difference-between-unipolar-polar-and-bipolar-line-coding-schemes/

Manchester-encoding-in-computer-network/

ML vs DL

A short video on machine learning vs deep learning

AI an introduction

Types of AI

What's AI?

Stages of AI

Components of AI

AI: Man-Made Thinking Power (MMTP)

Exam notes CSE all topics by GeeksforGeeks

operating-systems

geeksforgeeks.org/gate-cs-notes for all subjects

Types Software Testing

types-of-software-testing-complete-list

Subnet Masks and IP addresses

Understanding-tcp-ip-addressing-and-subnetting-basics

Collision Avoidance in wireless networks

collision-avoidance-in-wireless-networks

Hash Table: Data Structures

Hash_data_structure

Assembly language programming

Calculations by a processor using its own registers

Suppernetting: CIDR

CIDR or Supernetting

Network Design through subnetting using subnet masks

How to design networks using subnets.

Example 2

Example 3

Example 3 part 2

Sharing data between MAC and WIN machines

Data compatibility between Windows and Mac PC

OpenGL

what-is-opengl-and-how-to-start-learning-it

OSI and TCP/IP

OSI and TCP/IP models

DHCP Server: Dynamic Host Configuration Protocol

Whats a DHCP server

68K assembly programming

Motorola 68000 ISA

68000 Loops

Hubs, Switches and Routers

Difference between a Hub, switch and router

Difference between a Modem and a Router

How the DNS works

What is a Dynamic DNS

TCP vs UDP

RAID 0, 1, 5 and 10

RAID 5 and 6

Pseudo Code examples:

Example 1:

Example 2:

Example 3:

Example 4:

MATLAB: Learn and practice

Online MATLAB compiler

MATLAB tutorial

MATLAB with simulink

Matrixlab Matlab

Coursera learn matlab

ARM ISA

The ARM instruction set architecture

Hex calculator

Hex-to-decimal-converter 

Database Schema Design Tool: Data Modelling

Design a database schema online

Flow Charts

XML Schema : Examples

XML schema basics

Advanced XML Schema Data types

Data Mining: The Apriori Algorithm: Finding Frequent Itemset

Apriori Algorithm

Apriori algorithm with example 

Triggers in Oracle

Triggers in Oracle Vs MS SQL


Example of creating a Trigger in Oracle

CREATE OR REPLACE TRIGGER Print_salary_changes
  BEFORE DELETE OR INSERT OR UPDATE ON emp
  FOR EACH ROW
WHEN (NEW.EMPNO > 0)
DECLARE
    sal_diff number;
BEGIN
    sal_diff  := :NEW.SAL  - :OLD.SAL;
    dbms_output.put('Old salary: ' || :OLD.sal);
    dbms_output.put('  New salary: ' || :NEW.sal);
    dbms_output.put_line('  Difference ' || sal_diff);
END;

Testing: Error/mistakes -> some become bugs/faults -> some cause failure

There are two main testing(test case selection) strategies :

1. White box testing or Structural testing(Internal structure of the program is considered)

• Coverage based testing
• Cyclomatic complexity
• Mutation testing

   2. Black box testing or Functional testing (The internal structure of the program is ignored, and attempt is to analyze the code , which produces the outputs for the given input values).

• Boundary-value analysis
• Equivalence partitioning                                                                                                                                

Unit Testing Strategies - 1 IITKH

Unit Testing Strategies - 2 IITKH

State Transition Diagram: Software Engineering

State chart diagram
 https://www.youtube.com/watch?v=KBNSZp2Ysdg&feature=emb_logo

State chart diagram case study https://www.youtube.com/watch?time_continue=124&v=b_LXeysj7RY&feature=emb_logo

State machine diagram IITKH

State machine diagram of a bank ATM by IIT Kharagpur.

Example 1:

Example 2

Example 2

Example 3

Python: Plotting graphs

Plot  graph g(t) = (t^2, t^3 - t) for t(-2,2)

import matplotlib.pyplot as mp
import numpy as np
#Domain
t = np.arange(-2,2,0.001)
# create lists x and y which have all the values of x and y for the given domain
x = []
y = []

for i in t:
  x = x + [i*i]
  y = y + [i*i*i -3*i]
mp.plot(x, y)
  #mp.show()

# naming the x axis
mp.xlabel('x - axis')
# naming the y axis
mp.ylabel('y - axis')

# giving a title to my graph
mp.title('')

# function to show the plot
mp.show()

Output:

You can practice python at colab

System Flow Chart

Understanding System flow chart


System flow chart is not a flow chart for an algorithm.

Sample system flow chart

DFD in Software Engineering

How to build a DFD
DFD modelling technnique
DFD basics

Building blocks of a DFD

How DFD works:

next

finally

DFD rules:

DFD levels:

Level 0 or context diagram: Write the name of the software in just one circle, then draw all system users and connect them to the system.

Example 1: Context level DFD for a tic-tac-toe game we often play

here the player INPUTS his moves and the system OUTPUTS display.

Example 2

Level 0

Level 1

 example1 

example2

Level 2

Example 1

Example 2

Level 3





Synchronous processes: Two processes are connected directly through a arrow

Asynchronous processes : Two processes are connected via a DATA STORE

Output of the system such as a 'printout or display' is shown by a paralellogram

Burst Time of a CPU: OS fundamentals

CPU burst time

Activity Diagram

Activity Diagram : Case Study

Gantt Chart and Pert Chart: Software Engineering Project Scheduling

What is a Gantt Chart

Creating Gantt Chart using MS ExceL

Project Planning : Scheduling

Creating Gantt Chart Manually

PERT Chart:

GANTT Vs PERT

How to create a PERT chart
PERT creation in detail

PERT chart with milestones(days/weeks of completion of that milestone) indicated inside the node circle. As shown below:
PERT chart

 The 'letter' on the edges denote the task names, while the arrows indicate the flow of tasks.

In yet another example below, we also have mentioned the duration of each task along with their names in parenthesis

Cost-Benefit Analysis of Software Projects

What is CBA (cost-benefit analysis)?

UML in SE

UML and Software Engineering

SQL: We need JOINS to fetch combined info from two tables connected by foreign key(s)

Here is an example:

Using the AND operator in the WHERE clause to get a value from both tables each, as shown in query below:

Inserting date in Oracle table, for doing that we need to use the TO_DATE function like: TO_DATE('12/01/2016', 'DD/MM/YYYY'), as shown in example below:

Then SELECT for a specific DATE as given below:

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To get 'weekly' data (sum/count) :

suppose there is a 'sales' table having a 'sold_date' field, then

SELECT product_name, SUM(price) FROM sales WHERE sold_date <= (sysdate) AND sold_date >= (sysdate - 7);

Similarly for generating Monthly reports

SELECT product_name, SUM(price) FROM sales WHERE sold_date <= (sysdate) AND sold_date >= (sysdate - 30);


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We can have multiple AND operator in a SQL query

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Understanding SQL Transactions

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You can PRINT text in Oracle using AS clause: