Find sum of top-left to bottom-right diagonals in Java
The challenge
Given a square matrix (i.e. an array of subarrays), find the sum of values from the first value of the first array, the second value of …
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In-depth guides, insights, and best practices for modern software engineering
Sweeping trees in Java
The challenge
You will be given a list of strings representing nodes in a rooted tree. A visual representation of a very simple rooted tree could be: …
Read Article →Detect Pangram in Java
The challenge
A pangram is a sentence that contains every single letter of the alphabet at least once. For example, the sentence “The quick …
Read Article →Remove the parentheses in Java
The challenge
In this challenge you are given a string for example:
"example(unwanted thing)example"
Your task is to remove everything inside …
Read Article →What century is it in Java
The challenge
Return the century of the input year. The input will always be a 4 digit string, so there is no need for validation.
Examples …
Read Article →Lost number in number sequence in Java
The challenge
An ordered sequence of numbers from 1 to N is given. One number might have deleted from it, then the remaining numbers were mixed. Find …
Read Article →Simple string reversal in Java
The challenge
In this challenge, we are going to reverse a string while maintaining the spaces (if any) in their original place.
For example: …
Read Article →int32 to IPv4 in Java
The challenge
Take the following IPv4 address: 128.32.10.1
This address has 4 octets where each octet is a single byte (or 8 bits).
- 1st octet
128has …
Perimeter of squares in a rectangle in Java
The challenge
The drawing shows 6 squares the sides of which have a length of 1, 1, 2, 3, 5, 8. It’s easy to see that the sum of the perimeters …
Read Article →Palindrome chain length in Java
The challenge
Number is a palindrome if it is equal to the number with digits in reversed order. For example, 5, 44, 171, 4884 are palindromes, and 43 …
String array duplicates in Java
The challenge
You are given an array of strings and your task is to remove all consecutive duplicate letters from each string in the array.
For …
Read Article →Even or Odd Array Sum in Java
The challenge
Given a list of numbers, determine whether the sum of its elements is odd or even.
Give your answer as a string matching "odd" …