Finding the majority element in an array

Problem Statement Given an array of size n, find the majority element. What is the majority element in an array? The majority element is the element that occurs more than half of the size of the array i.e the element should occur more than (⌊ N/2 ⌋) times. You may assume that the array is non-empty…

https://thecodingbot.com/finding-the-majority-element-in-an-array/

Leetcode – 169. Majority Element

Problem Statement Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times. You may assume that the array is non-empty and the majority element always exist in the array. Example 1: Input: [3,2,3] Output: 3 Example 2: Input: [2,2,1,1,1,2,2] Output: 2 (you can solve the…

https://thecodingbot.com/leetcode-169-majority-element/

How to customize Django admin panel cookbook

LeetCode – 182. Duplicate Emails

Write a SQL query to find all duplicate emails in a table named Person. +----+---------+ | Id | Email | +----+---------+ | 1 | a@b.com | | 2 | c@d.com | | 3 | a@b.com | +----+---------+ For example, your query should return the following for the above table: +---------+ | Email | +---------+ | a@b.com…

https://thecodingbot.com/leetcode-182-duplicate-emails/

LeetCode – 595. Big Countries

Problem Statement There is a table World +-----------------+------------+------------+--------------+---------------+ | name | continent | area | population | gdp | +-----------------+------------+------------+--------------+---------------+ | Afghanistan | Asia | 652230 | 25500100 | 20343000 | | Albania | Europe | 28748 | 2831741 | 12960000 | | Algeria | Africa | 2381741 | 37100000 | 188681000 | | Andorra |…

https://thecodingbot.com/leetcode-595-big-countries/

LeetCode – 627. Swap Salary

Problem Statement Given a table salary, such as the one below, that has m=male and f=female values. Swap all f and m values (i.e., change all f values to m and vice versa) with a single update…

https://thecodingbot.com/leetcode-627-swap-salary/

LeetCode – 620. Not Boring Movies

Problem Statement X city opened a new cinema, many people would like to go to this cinema. The cinema also gives out a poster indicating the movies’ ratings and descriptions. Please write a SQL query…

https://thecodingbot.com/leetcode-620-not-boring-movies/

Please fill the survey

LeetCode – 197. Rising Temperature

Given a Weather table, write a SQL query to find all dates’ Ids with higher temperature compared to its previous (yesterday’s) dates. +---------+------------------+------------------+ | Id(INT) | RecordDate(DATE) | Temperature(INT) | +---------+------------------+------------------+ | 1 | 2015-01-01 | 10…

https://thecodingbot.com/leetcode-197-rising-temperature/

Similar problem asked in google, amazon. Try out yourself.

Today's topic is Design Patterns in C++

Design patterns : In software engineering, a design pattern is a general repeatable solution to a commonly occurring problem in software design. A design pattern isn't a finished design that can be transformed directly into code. It is a description or template for how to solve a problem that can be used in many different situations.

Here are resources:

Blogs:

1. https://www.bogotobogo.com/DesignPatterns/introduction.php
2. https://readthedocs.org/projects/cpp-design-patterns/downloads/pdf/latest/
3. https://caiorss.github.io/C-Cpp-Notes/cpp-design-patterns.html

Youtube:

1. cppcon 2019 modern C++ design pattern : https://www.youtube.com/watch?v=MdtYi0vvct0
2. https://www.youtube.com/watch?v=j9arNRRoPe8 (1 hour tutorial)
3. Playlist: https://www.youtube.com/watch?v=8tbxQ2IUtvE&list=PLiLpmqwkwkCsgR__zwKVB0s4bIYrF8vWu

Paid Courses:

1. https://www.pluralsight.com/paths/c-design-patterns

Books:

1. Modern C++ Design
2. Design Patterns: Elements of Reusable Object-Oriented Software

Rearrange a linked list such that all even index nodes come after all odd index nodes

Problem Statement Given a singly linked list, group all odd nodes together followed by all the even nodes. Please note here we are talking about the node number and not the value in the nodes.…

https://thecodingbot.com/rearrange-a-linked-list-such-that-all-even-index-nodes-come-after-all-odd-index-nodes/

Today is Python day and topic for today is "Mutable and Immutable Objects in Python"

You might use Python daily, but do you really go into details to know what you are doing and most importantly why are you doing certain operation?

Mutable and Immutable objects are one of the most important topic in Python and you might be asked about them in any interview.

Complete tutorial: https://medium.com/@meghamohan/mutable-and-immutable-side-of-python-c2145cf72747
Or, Complete tutorial 2: https://hackernoon.com/python-objects-and-mutability-397f7de38bb5
Or, Complete tutorial 3: https://thecodingbot.com/pythons-built-in-id-with-examples/ (contains multiple examples supporting it)

596. Classes More Than 5 Students

Problem Statement There is a table courses with columns: student and class Please list out all classes which have more than or equal to 5 students. For example, the table: +---------+------------+ | student | class | +---------+------------+ | A |…

https://thecodingbot.com/596-classes-more-than-5-students/

It is sunday today and I post from random topic. Today, let's have some machine learning as our breakfast.

Here's a two part guide to hypertune the XGboost algorithm(very very important for kaggle winning)

Tut 1: https://towardsdatascience.com/doing-xgboost-hyper-parameter-tuning-the-smart-way-part-1-of-2-f6d255a45dde
------------------------+----------------+-------------+
Another tutorial:

Part 1 - https://blog.cambridgespark.com/getting-started-with-xgboost-3ba1488bb7d4

Part 2 - https://blog.cambridgespark.com/hyperparameter-tuning-in-xgboost-4ff9100a3b2f


Both are nice reads. Enjoy.
(thecodingbot.com, @computerprogrammingcodingbot)

LeetCode – 1295. Find Numbers with Even Number of Digits

Problem Statement Given an array nums of integers, return how many of them contain an even number of digits. Example 1: Input: nums = [12,345,2,6,7896] Output: 2 Explanation: 12 contains 2 digits (even number of digits).  345 contains 3…

https://thecodingbot.com/leetcode-1295-find-numbers-with-even-number-of-digits/

Python’s built-in id() method with examples

In this tutorial, we will talk about a built-in method in Python, and that method is id(). We will talk about its syntax, where is it used, what parameters it takes and what value it returns.…

https://thecodingbot.com/pythons-built-in-id-with-examples/

LeetCode – 1108. Defanging an IP Address

Problem Statement Given a valid (IPv4) IP address, return a defanged version of that IP address. A defanged IP address replaces every period "." with "[.]". Example 1: Input: address = "1.1.1.1" Output: "1[.]1[.]1[.]1" Example 2: Input: address = "255.100.50.0" Output: "255[.]100[.]50[.]0"…

https://thecodingbot.com/leetcode-1108-defanging-an-ip-address/

Hi, Today's topic is Testing in Django

Here are some resources:

Blog

1. https://realpython.com/testing-in-django-part-1-best-practices-and-examples/
2. https://realpython.com/testing-in-django-part-2-model-mommy-vs-django-testing-fixtures/

Youtube

1. https://youtu.be/WWa4bzTJZgI
2. https://youtu.be/6tNS--WetLI

Happy Coding (thecodingbot.com,t.me/computerprogrammingcodingbot)

Github Project for testing guide in Django:

1. https://github.com/toastdriven/guide-to-testing-in-django
2. https://github.com/wsvincent/django-testing-tutorial