HackerRank

There is a large pile of socks that must be paired by color.

An avid hiker keeps meticulous records of their hikes.

There is a new mobile game that starts with consecutively numbered clouds.

There is a string, , of lowercase English letters that is repeated infinitely many times.

There are 16 hourglasses in arr. An hourglass sum is the sum of an hourglass' values.

A left rotation operation on an array shifts each of the array's elements 1 unit to the left.

It is New Year's Day and people are in line for the Wonderland rollercoaster ride.

You are given an unordered array consisting of consecutive integers ∈ [1, 2, 3, ..., n] without any duplicates.

Given an array of integers, sort the array in ascending order using the Bubble Sort algorithm above.

Mark and Jane are very happy after having their first child. Their son loves toys, so Mark wants to buy some.

Comparators are used to compare two objects. In this challenge, you'll create a comparator and use it to sort an array.

HackerLand National Bank has a simple policy for warning clients about possible fraudulent account activity.

A student is taking a cryptography class and has found anagrams to be very useful.

Your task is to change it into a string such that there are no matching adjacent characters.

Harold is a kidnapper who wrote a ransom note, but now he is worried it will be traced back to him through his handwriting.

Given two strings, determine if they share a common substring. A substring may be as small as one character.

Given an array of integers, find the minimum absolute difference between any two elements in the array.

Lena is preparing for an important coding competition that is preceded by a number of sequential preliminary contests.