How to Validate an IP Address in Golang
The challenge
Write an algorithm that will identify valid IPv4 addresses in dot-decimal format. IPs should be considered valid if they consist of four …
Read Article →Technical Articles
In-depth guides, insights, and best practices for modern software engineering
How to Fold an Array in Java
The challenge
In this challenge, you have to write a method that folds a given array of integers by the middle x-times.
An example says more than a …
Read Article →Formatting Strings with Fmt in Golang
Fmt provides printing to standard output (usually the console) and formatting of strings capabilities.
The basics of Print and Println
The main …
Read Article →Delete Occurrences of an Element if it occurs more than N times in Java
The challenge
Given a list lst and a number N, create a new list that contains each number of lst at most N times without reordering. For example if N …
Read Article →How to Read from Standard Input in Golang
Reading from “standard input” is really useful if you are making a command-line application and require user input.
package main
import ( …How to Install Golang on WSL/WSL2
If you need to install Golang on WSL under Windows 10 or higher, you can follow these few steps.
First remove any old versions lying around
sudo rm …How to Validate Phone Numbers in Java
The challenge
Write a function that accepts a string, and returns true if it is in the form of a phone number.
Assume that any integer from 0-9 in any …
How to Sort Array by Frequency in Java
The challenge
Sort elements in an array by decreasing frequency of elements. If two elements have the same frequency, sort them by increasing value. …
Read Article →How to Calculate String Rotation in Java
The challenge
Write a function that receives two strings and returns n, where n is equal to the number of characters we should shift the first string …
Read Article →Compare Strings by Sum of Chars in Java
The challenge
Compare two strings by comparing the sum of their values (ASCII character code).
- For comparing treat all letters as UpperCase
null …
How to Add Two Integers Without Arithmetic Operator in Java
The challenge
Given two integers a, b, find The sum of them, BUT You are not allowed to use the operators + and –
- The numbers (a,b) may be positive …
Counting Method VarArgs in Java
The challenge
Count how many arguments a method is called with.
Examples
args_count(1, 2, 3) -> 3
args_count(1, 2, 3, 10) -> 4