How to Reverse Letters in Kotlin
The challenge
Given a string str, reverse it omitting all non-alphabetic characters.
Examples:
For str = "krishan", the output should be …
Kotlin
19 articles about kotlin development, tools, and best practices
How to Get the ASCII Value of Character in Kotlin
The challenge
Get the ASCII value of a character.
The solution in Kotlin
Option 1:
val getAscii = Char::toInt
Option 2:
fun getAscii(c: Char) = c.code …How to use Coroutines in Kotlin
Coroutines are a way to handle multithreading in Kotlin, read more about it from the official docs: …
Read Article →The Pair Type in Kotlin
val pair: Pair<String, Int> = "myKey" to 2
What is a Pair Type?
A utility class when you want to return 2 values that are not related …
Read Article →Deconstruction in Kotlin
There are times when you need to extract an object into a number of variables.
Let’s take the example below:
val (id, name, position, …What is a Unit in Kotlin?
Unit corresponds to the void keyword in Java.
What is a Unit in Kotlin?
If you have a function that does not return a value, you can return a Unit …
How to declare a Function in Kotlin?
Functions are reusable pieces of code, often called Blocks, that as the name suggests, act as building blocks to piece together a program.
Each …
Read Article →The differences between Val and Var in Kotlin
Among all the many keywords that Kotlin comes with, there exists val and var. What are they used for? What are the differences, and why would you use …
Build a pile of Cubes in Kotlin
The challenge
Your task is to construct a building which will be a pile of n cubes. The cube at the bottom will have a volume of n^3, the cube above …
Read Article →Which x for that sum in Kotlin
The challenge
Consider the sequence U(n, x) = x + 2x**2 + 3x**3 + .. + nx**n where x is a real number and n a positive integer.
When n goes to …
Invert values in Kotlin
The challenge
Given a set of numbers, return the additive inverse of each. Each positive becomes negatives, and the negatives become positives. …
Read Article →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). …
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 …
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