How to find out Cluster Info in Kubernetes
In Kubernetes, a cluster is a group of machines working together.
By running the kubectl cluster-info command, we can find out high level information …
Technical Articles
In-depth guides, insights, and best practices for modern software engineering
How to set and use a kubeconfig in Kubernetes
The kubeconfig file is the main configuration file that allows access to a Kubernetes cluster.
When you first create your Kubernetes cluster, you are …
Read Article →How to Map over a List of Lists in Java
The challenge
Write a function which maps a function over the lists in a list:
public static <T,R> R[][] gridMap(Function<T,R> fn, T[][] …How to Differentiate a Polynomial in Java
The challenge
Create a function that differentiates a polynomial for a given value of x.
Your function will receive 2 arguments: a polynomial as a …
Read Article →Find the Sums of Perfect Squares in Java
The challenge
The task is simply stated. Given an integer n (3 < n < 10<sup>9</sup>), find the length of the smallest list of …
[Solved] Error: Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:2.4.4:repackage (repackage)
If you have come across this error when trying to build and deploy your Spring Boot Maven application then this post will help you!
Error: Failed to …
[Solved] No main manifest attribute Solution for Jar/Maven/Gradle/Spring Boot
You’ve built a Java project and packaged a .jar file.
You are ready to run it outside your IDE, or deploy it somewhere.
When you run it using …
Read Article →[Solved] Error – The following untracked working tree files would be overwritten by merge
So you just tried to do a git pull and got the following error:
error: The following untracked working tree files would be overwritten by merge:
How …
Read Article →How to Strip Script Tags in PHP
If you have some HTML input submitted from a user to your application, before saving it to the database, you may want to strip all <script> tags …
How to Make a Spiral in Java
The challenge
Your task, is to create a NxN spiral with a given size.
For example, spiral with size 5 should look like this:
00000 ....0 000.0 0...0 …Read Article →
Find the Longest Common Subsequence in Java
The challenge
from Wikipedia:
The longest common subsequence (LCS) problem is the problem of finding the longest subsequence common to all sequences …
Find First and Last Position of Element in Sorted Array in Java
The challenge
Given an array of integers nums sorted in ascending order, find the starting and ending position of a given target value.
If target is …
Determine if Number is a Power of Three in Java
The challenge
Given an integer n, return true if it is a power of three. Otherwise, return false.
An integer n is a power of three, if there exists an …
How to Count Binary Substrings in Java
The challenge
Give a string s, count the number of non-empty (contiguous) substrings that have the same number of 0’s and 1’s, and all the …
How to Download a CSV file using Javascript
Ever wanted to generate a CSV (comma separated values) file directly from the browser, using Javascript? Instead of going to the server..
Look no …
Read Article →Array Range between Integers in Java
The challenge
Complete the function that takes two integers (a, b, where a < b) and return an array of all integers between the input parameters, …
How to clone a table structure in MySQL
I have often needed to clone a table without it’s data in MySQL.
Oftentimes this has been because I have a continually growing temporary table …
Read Article →Number of Rectangles in a Grid in Java
The challenge
Given a grid of size m x n, calculate the total number of rectangles contained in this rectangle. All integer sizes and positions are …
Read Article →Longest vowel chain in Java
The challenge
The vowel substrings in the word codewarriors are o,e,a,io. The longest of these has a length of 2. Given a lowercase string that has …
Determine Unique String Characters in Java
The challenge
In this challenge, you will be given two strings a and b and your task will be to return the characters that are not common in the two …
Difference of Volumes of Cuboids in Java
The challenge
In this simple exercise, you will create a program that will take two lists of integers, a and b. Each list will consist of 3 positive …
Sort by binary ones in Java
The challenge
In this example you need to implement a function that sort a list of integers based on it’s binary representation.
The rules are …
Read Article →Binomial Expansion in Java
The challenge
Write a program that can do some algebra. Write a function expand that takes in an expression with a single, one character variable, and …
Consecutive strings in Java
The challenge
You are given an array(list) strarr of strings and an integer k. Your task is to return the first longest string consisting of k …