Spring Boot no main manifest attribute, in
You have created a ./target/java -jar <app>.jar yet receive a spring boot no main manifest attribute, in …
Technical Articles
In-depth guides, insights, and best practices for modern software engineering
Moduli number system in Kotlin
The challenge
A number system with moduli is defined by a vector of k moduli, [m1,m2, ···,mk].
The moduli must be pairwise co-prime, which means that, …
Smallest possible sum in Kotlin
The challenge
Given an array X of positive integers, its elements are to be transformed by running the following operation on them as many times as …
Read Article →Floating-point Approximation in Kotlin
The challenge
Given
- a semi-inclusive interval
I = [l, u)(l is in interval I but u is not)landubeing floating numbers(0 <= l < u), - an …
Multiplication table in Kotlin
The challenge
Create an NxN multiplication table, of size provided in parameter.
for example, when given size is 3:
1 2 3
2 4 6
3 6 9
for given …
Read Article →Strip Comments in Kotlin
The challenge
Complete the solution so that it strips all text that follows any of a set of comment markers passed in. Any whitespace at the end of …
Read Article →Experimenting with a sequence of complex numbers in Kotlin
The challenge
Consider the sequence S(n, z) = (1 - z)(z + z**2 + z**3 + ... + z**n) where z is a complex number and n a positive integer (n > 0). …
pt-online-schema-change Add Index
Percona has a great toolkit that allows you to perform schema changes on a MySQL or MariaDB database without any downtime, it works by creating a new …
Read Article →Sums of Parts in Kotlin
The challenge
Let us consider this example (array written in general format):
ls = [0, 1, 3, 6, 10]
Its following parts:
ls = [0, 1, 3, 6, 10]
ls = …Diophantine Equation in Kotlin
The challenge
In mathematics, a Diophantine equation is a polynomial equation, usually with two or more unknowns, such that only the integer solutions …
Read Article →Matrix Addition in Java
The challenge
Write a function that accepts two square matrices (N x N two dimensional arrays), and return the sum of the two. Both matrices being …
Numbers that are a power of their sum of digits in Java
The challenge
The number 81 has a special property, a certain power of the sum of its digits is equal to 81 (nine squared). Eighty one (81), is the …
Read Article →Integer triangles in Java
The challenge
You have to give the number of different integer triangles with one angle of 120 degrees which perimeters are under or equal a certain …
Read Article →Minimum path in squares in Java
The challenge
You’re given a square consisting of random numbers, like so:
var square = [
[1,2,3],
[4,8,2],
[1,5,3]
];
Your job is …
Read Article →Pascal’s Diagonals in Java
The challenge
Create a function that returns an array containing the first l digits from the nth diagonal of Pascal’s triangle.
n = 0 should …
Maximum Contiguous Sum in Java
The challenge
Given an unsorted array of integer values, find the maximum positive sum of any contiguous range within the array.
An array containing …
Read Article →Fibonacci Streaming in Java
The challenge
You’re going to provide a needy programmer a utility method that generates an infinite sized, sequential IntStream which contains …
Base-2 in Java
The challenge
In this challenge you must convert integers numbers from and to a negative-base binary system.
Negative-base systems can accommodate all …
Read Article →Unique digits sequence in Java
The challenge
Consider the following series:
0,1,2,3,4,5,6,7,8,9,10,22,11,20,13,24...There is nothing special between numbers `` and 10.
Let’s …
Read Article →Palindrome integer composition in Java
The challenge
The palindromic number 595 is interesting because it can be written as the sum of consecutive squares: 6^2 + 7^2 + 8^2 + 9^2 + 10^2 + …
Count IP Addresses in Java
The challenge
Implement a function that receives two IPv4 addresses, and returns the number of addresses between them (including the first one, …
Read Article →Shortest Knight Path in Java
The challenge
Given two different positions on a chess board, find the least number of moves it would take a knight to get from one to the other. The …
Read Article →All Balanced Parentheses in Java
The challenge
Write a function that makes a list of strings representing all of the ways you can balance n pairs of parentheses
Examples …
Read Article →Human readable duration format in Java
The challenge
Your task in order to complete this challenge is to write a function which formats a duration, given as a number of seconds, in a …
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