How to Encrypt Words in Java
The challenge
You want to create secret messages which must be deciphered.
Here are the conditions:
- Your message is a string containing space …
Technical Articles
In-depth guides, insights, and best practices for modern software engineering
Bit Counting in Golang
The challenge
Write a function that takes an integer as input, and returns the number of bits that are equal to one in the binary representation of …
Read Article →How to Find Next Higher Number with Same Bits in Golang
The challenge
Find the next higher number (int) with same ‘1’- Bits.
I.e. as much 1 bits as before and output next higher than input. Input is …
How to Find the First Non-Repeating Character in Golang
The challenge
Write a function named first_non_repeating_letter that takes a string input, and returns the first character that is not repeated …
How to Find the Last Fibonacci Digit in Golang
The challenge
Return the last digit of the nth element in the Fibonacci sequence (starting with 1,1, to be extra clear, not with 0,1 or other …
Read Article →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 →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 –
Notes
- The numbers (a,b) may be …
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
The solution in …
Read Article →How to Sum Consecutives in Java
The challenge
You are given a list/array which contains only integers (positive and negative). Your job is to sum only the numbers that are the same …
Read Article →Replacing Occurences of Words in Java
The challenge
You are given a string. You must replace any occurrence of the sequence coverage by covfefe, however, if you don’t find the word …
Convert String to LeetSpeak in Java
The challenge
Your task is to write a function toLeetSpeak that converts a regular english sentence to Leetspeak.
More about LeetSpeak You can read at …
Read Article →Ordered Count of Characters in Python
The challenge
Count the number of occurrences of each character and return it as a list of tuples in order of appearance. For empty output return an …
Read Article →Credit Card Issuer Checking in Java
The challenge
Given a credit card number we can determine who the issuer/vendor is with a few basic knowns.
Complete the function getIssuer() that …
Find Count of Most Frequent Item in an Array in Java
The challenge
Complete the function to find the count of the most frequent item of an array. You can assume that input is an array of integers. For an …
Read Article →Return Nth Smallest Element in Java
The challenge
Given an array/list [] of integers, Find the Nth smallest element in this array of integers
Notes
- Array/list size is at least 3 . …