the year 1800 was a leap year in the Julian calendar. However, by that time, many countries had already switched to the Gregorian calendar, which did not consid
Read more →An array is a data structure that stores elements of the same type in a contiguous block of memory
Read more →Watson likes to challenge Sherlock's math ability. He will provide a starting and ending value that describe a range of integers.
Read more →You have two strings of lowercase English letters. You can perform two types of operations on the first string
Read more →Given a string of lowercase letters in the range ascii[a-z], determine the index of a character that can be removed to make the string a palindrome.
Read more →Consider an undirected graph where each edge weighs 6 units. Each of the nodes is labeled consecutively from 1
Read more →Given an array of bird sightings where every element represents a bird type id
Read more →A bracket is considered to be any one of the following characters: (, ), {, }, [, or ].
Read more →Given an array of integers, where all elements but one occur twice, find the unique element.
Read more →Given a pointer to the head of a linked list, insert a new node before the head
Read more →In this challenge, you will determine whether a string is funny or not. To determine whether a string is funny.
Read more →Mark and Jane are very happy after having their first child. Their son loves toys
Read more →Given a pointer to the root of a binary tree, you need to print the level order traversal of this tree
Read more →Given a 2D array, an hourglass is a subset of values with indices falling in the following pattern
Read more →Delete the node at a given position in a linked list and return a reference to the head node
Read more →Given a square grid of characters in the range ascii[a-z], rearrange elements of each row alphabetically, ascending.
Read more →Two children, Lily and Ron, want to share a chocolate bar. Each of the squares has an integer on it.
Read more →A Discrete Mathematics professor has a class of students. Frustrated with their lack of discipline.
Read more →A driver is driving on the freeway. The check engine light of his vehicle is on, and the driver wants to get service immediately.
Read more →We say that a string contains the word hackerrank if a of its characters spell the word hackerrank. Remeber that a subsequence maintains the order of characters
Read more →Given the time in numerals we may convert it into words, as shown below
Read more →There is a large pile of socks that must be paired by color. Given an array of integers representing the color of each sock, determine how many pairs of socks.
Read more →In a previous challenge you implemented the Insertion Sort algorithm. It is a simple sorting algorithm that works well with small or mostly sorted data.
Read more →HackerLand Enterprise is adopting a new viral advertising strategy
Read more →The distance between two array values is the number of indices between them. Given , find the minimum distance between any pair of equal elements in the array.
Read more →We define super digit of an integer using the following rules
Read more →The height of a binary tree is the number of edges between the tree's root and its furthest leaf.
Read more →Given a pointer to the head node of a linked list and an integer to insert at a certain position
Read more →Louise joined a social networking site to stay in touch with her friends. The signup page required her to input a name and a password
Read more →Its base and height are both equal to . It is drawn using # symbols and spaces. The last line is not preceded by any spaces.
Read more →In Insertion Sort Part 1, you inserted one element into an array at its correct sorted position. Using the same approach repeatedly, can you sort an entire.
Read more →There is a string of lowercase English letters that is repeated infinitely many times. Given an integer
Read more →You’re given the pointer to the head nodes of two linked lists. Compare the data in the nodes of the linked lists to check if they are equal. If all data.
Read more →David has several containers, each with a number of balls in it. He has just enough containers to sort each type of ball he has into its own container.
Read more →This exercise focuses on traversing a linked list.
Read more →You will be given a list of 32 bit unsigned integers. Flip all the bits ( and ) and return the result as an unsigned integer.
Read more →One common task for computers is to sort data. For example, people might want to see all their files on a computer sorted by size
Read more →Given two arrays of integers, find which elements in the second array are missing from the first array.
Read more →Given the pointer to the head node of a linked list, change the next pointers of the nodes so that their order is reversed.
Read more →A video player plays a game in which the character competes in a hurdle race.
Read more →Marc loves cupcakes, but he also likes to stay fit. Each cupcake has a calorie count, and Marc can walk a distance to expend those calories.
Read more →In this challenge, you are required to implement inorder traversal of a tree.
Read more →Alef the Frog is in an two-dimensional maze represented as a table.
Read more →John Watson knows of an operation called a right circular rotation on an array of integers.
Read more →There is a new mobile game that starts with consecutively numbered clouds.
Read more →Sherlock considers a string to be valid if all characters of the string appear the same number of times.
Read more →You are choreographing a circus show with various animals. For one act, you are given two kangaroos on a number line ready to jump in the positive direction.
Read more →Given the pointer to the head node of a doubly linked list, reverse the order of the nodes in place.
Read more →Given pointers to the head nodes of linked lists that merge together at some point.
Read more →A child is playing a cloud hopping game. In this game, there are sequentially numbered clouds that can be thunderheads or cumulus clouds.
Read more →Given a pointer to the head of a singly-linked list, print each value from the reversed list. If the given list is empty, do not print anything.
Read more →Given a reference to the head of a doubly-linked list and an integer.
Read more →The factorial of the integer , written , is defined as
Read more →We consider two strings to be anagrams of each other if the first string's letters can be rearranged to form the second string.
Read more →Given a pointer to the head of a linked list and a specific position, determine the data value at that position
Read more →You are given a string containing characters A and B only. Your task is to change it into a string such that there are no matching adjacent characters.
Read more →Complete the function in the editor below. It received parameter: a pointer to the root of a binary tree. It must print the values in the tree's postorder.
Read more →It must print the values in the tree's preorder traversal as a single line of space-separated values.
Read more →Taum is planning to celebrate the birthday of his friend, Diksha. There are two types of gifts that Diksha wants from Taum
Read more →Given an array of integers, determine the minimum number of elements to delete to leave only elements of equal value.
Read more →Given an array of integers and a positive integer , determine the number of pairs where and + is divisible by .
Read more →You are given the pointer to the head node of a sorted linked list, where the data in the nodes is in ascending order.
Read more →Many of the challenges on HackerRank are difficult and assume that you already know the relevant algorithms.
Read more →A jail has a number of prisoners and a number of treats to pass out to them
Read more →We define a magic square to be an matrix of distinct positive integers from to where the sum of any row, column, or diagonal of length is always equal
Read more →A pangram is a string that contains every letter of the alphabet. Given a sentence determine whether it is a pangram in the English alphabet
Read more →Given a set of distinct integers, print the size of a maximal subset of where the sum of any numbers in is not evenly divisible by k.
Read more →There are a number of people who will be attending ACM-ICPC World Finals.
Read more →There is a sequence of words in CamelCase as a string of letters, s, having the following properties:
Read more →The absolute difference is the positive difference between two values is written
Read more →You are given a pointer to the root of a binary search tree and values to be inserted into the tree.
Read more →You are given the pointer to the head node of a linked list and an integer to add to the list.
Read more →You have an empty sequence, and you will be given queries. Each query is one of these three types.
Read more →A linked list is said to contain a cycle if any node is visited more than once while traversing the list.
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