How to Find the Missing Alphabets in Python
The challenge
Task
Given string s, which contains only letters from a to z in lowercase.
A set of the alphabet is given by abcdefghijklmnopqrstuvwxyz. …
Technical Articles
In-depth guides, insights, and best practices for modern software engineering
How to move MySQL database to another drive
Step 1:
Login to your MySQL server, enter your password when prompted:
mysql -u root -p
Find out where the data directory is located:
mysql> select …How to Find the Sum of Prime-Indexed Elements in Go
The challenge
You will be given an integer array and your task is to return the sum of elements occupying prime-numbered indices.
The first element of …
Read Article →Longest Alphabetical Substring (Python)
The challenge
Find the longest substring in alphabetical order. If there are multiple substrings of the same maximum length, return the one that …
Read Article →Calculate the Most Frequent Weekdays in Go
The challenge
What is your favourite day of the week? Check if it’s the most frequent day of the week in the year.
You are given a year as …
Read Article →Return Index of Matching Closing Bracket in Go
The challenge
In this challenge, you will be given a string with brackets and an index of an opening bracket and your task will be to return the index …
Read Article →How to Presign an S3 URL in AWS using AWS CLI
You can use the AWS CLI to presign URLs so that objects in S3 can be shared publicly even if they are set as private.
Presigned URLs are great for …
Read Article →How to Download using Aria2c with Multiple Connections
If you use aria2c to download files using the command-line, then you can also use it to download using multiple connections.
aria2c -x16 -s16 …How to Parse HTML/CSS Colors in Java
The challenge
In this challenge, you parse RGB colors represented by strings. The formats are primarily used in HTML and CSS. Your task is to …
Read Article →Solving Simple Transposition in Java
The challenge
Simple transposition is a basic and simple cryptography technique. We make 2 rows and put first a letter in Row 1, the second in Row 2, …
Read Article →How to Binary to Text (ASCII) Conversion in Python
The challenge
Write a function that takes in a binary string and returns the equivalent decoded text (the text is ASCII encoded).
Each 8 bits on the …
Read Article →How to Find the Row of the Odd Triangle in Python
The challenge
Given a triangle of consecutive odd numbers:
1
3 5
7 9 11
13 15 17 19
21 23 …Solving Number Zoo Patrol in Python
The challenge
Write a function that takes a shuffled list of unique numbers from 1 to n with one element missing (which can be any number including n …
Common AWS CDK CLI Commands
The AWS Cloud Development Kit (CDK) comes with numerous CLI commands.
| Command | Function … |
|---|
How to Create an S3 bucket with PublicRead in CloudFormation
Here’s a minimal CloudFormation template for creating an S3 bucket with public read access. This is useful for hosting static assets like …
Read Article →How to Create a VPC in CloudFormation
It’s very easy to deploy a VPC using CloudFormation:
AWSTemplateFormatVersion: 2010-09-09
Description: Deploy a VPC
Resources:
VPC:
Type: …How to Setup Git on EC2 for AWS CodeCommit
Connect to the instance:
chmod 400 KEYPAIR.pem
ssh -i KEYPAIR.pem ec2-user@EC2PublicIP
Install Git:
sudo yum install -y git
Setup Git Credential …
Read Article →The Difference of 2 in Java
The challenge
The objective is to return all pairs of integers from a given array of integers that have a difference of 2.
The resulting array should …
Read Article →How to Make the Deadfish Swim in Java
The challenge
Write a simple parser that will parse and run Deadfish.
Deadfish has 4 commands, each 1 character long:
iincrements the value …
How to Write Number in Expanded Form in Java
The challenge
You will be given a number and you will need to return it as a string in Expanded Form.
Examples:
Challenge.expandedForm(12); // Should …Is a Number Prime in Java
The challenge
Define a function that takes one integer argument and returns a logical value true or false depending on if the integer is a prime.
Per …
Read Article →How to Calculate Minutes to Midnight in Java
The challenge
Write a function minutesToMidnight(d) that will take a date object as the parameter. Return the number of minutes in the following …
Read Article →How to Change the Timestamp of a File on Mac/Linux
If you have a file on your machine, and you want to change the created/modified time/date stamp, then you can use the touch command.
touch -t …How to Round up to the Next Multiple of 5 in Python
The challenge
Given an integer as input, can you round it to the next (meaning, “higher”) multiple of 5?
Examples:
input: output:
0 …