How to Return Random Values in Java
The challenge
Ghost objects are instantiated without any arguments.
Ghost objects are given a random color attribute of white" or …
Read Article →Technical Articles
In-depth guides, insights, and best practices for modern software engineering
How to Compare Version Numbers in Java
The challenge
Compare two version numbers version1 and version2.
If <em>version1</em> > <em>version2</em> …
How to Return the First N Elements in Java
The challenge
Create a method take that accepts a list/array and a number n, and returns a list/array array of the first n elements from the …
Read Article →How to Search a 2d Matrix/Array in Java
The challenge
Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties:
- Integers in each …
Calculate the Surface Area and Volume of a Box with Java
The challenge
Write a function that returns the total surface area and volume of a box as an array: [area, volume]
The solution in Java
We know that …
Read Article →Find Numbers which are Divisible by given Number in Java
The challenge
Complete the function which takes two arguments and returns all numbers which are divisible by the given divisor. First argument is an …
Read Article →How to Split a Subdirectory to a New Git Repository and Keep the History
There comes a time when you need to split out a subdirectory into it’s own git repo.
This is a very simple task if you don’t care about …
Read Article →Get the Maximum XOR of Two Numbers in an Array in Java
The challenge
Given a non-empty array of numbers, a, a1, a2, … , an-1, where 0 ≤ ai < 231.
Find the maximum result of ai XOR aj, where 0 ≤ i, j …
Read Article →How to Get the Opposite of a Number in Java
The challenge
Given a number, find its opposite.
Examples:
1: -1
14: -14
-34: 34
The solution in Java
We return the number itself multiplied by a …
Read Article →How to Find the Area or Perimeter of a 4-sided Polygon using Java
The challenge
You are given the length and width of a 4-sided polygon. The polygon can either be a rectangle or a square.
If it is a square, return …
How to Parse Int from Char in Java
The challenge
We take in a String where the first place contains a number, write a function that takes in this String and returns an int containing …
How to Search a Binary Tree in Java
The challenge
Given a sorted (in ascending order) integer array nums of n elements and a target value, write a function to search target in nums. If …