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2024

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2023

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2018

[Lucky Algorithm] Equalize the Array (72/77)

less than 1 minute read

Equalize the Array (Hacker Rank) Karl has an array of integers. He wants to reduce the array until all remaining elements are equal. Determine the fewest num...

[Lucky Algorithm] Encryption (71/77)

less than 1 minute read

Encryption (Hacker Rank) An English text needs to be encrypted using the following encryption scheme. First, the spaces are removed from the text. Let be th...

[Lucky Algorithm] Angry Professor (69/77)

less than 1 minute read

Angry Professor (Hacker Rank) A Discrete Mathematics professor has a class of students. Frustrated with their lack of discipline, he decides to cancel class ...

[Lucky Algorithm] TArmy Game (65/77)

less than 1 minute read

Army Game (Hacker Rank) Luke is daydreaming in Math class. He has a sheet of graph paper with rows and columns, and he imagines that there is an army base i...

[Lucky Algorithm] Utopian Tree (64/77)

less than 1 minute read

Utopian Tree (Hacker Rank) The Utopian Tree goes through 2 cycles of growth every year. Each spring, it doubles in height. Each summer, its height increases ...

[Lucky Algorithm] Maximizing XOR (63/77)

less than 1 minute read

Maximizing XOR (Hacker Rank) Given two integers, and , find the maximal value of xor , written , where and satisfy the following condition:

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2017

[Lucky Algorithm] Max Min (62/77)

less than 1 minute read

Max Min (Hacker Rank) You will be given a list of integers, , and a single integer . You must create an array of length from elements of such that its unfa...

[Lucky Algorithm] Cavity Map (61/77)

1 minute read

Cavity Map (Hacker Rank) You are given a square map as a matrix of integer strings. Each cell of the map has a value denoting its depth. We will call a cell ...

[Lucky Algorithm] Lonely Integer (55/77)

less than 1 minute read

Lonely Integer (Hacker Rank) Consider an array of integers, , where all but one of the integers occur in pairs. In other words, every element in occurs exa...

[Lucky Algorithm] Marc’s Cakewalk (54/77)

less than 1 minute read

Marc’s Cakewalk (Hacker Rank) Marc loves cupcakes, but he also likes to stay fit. He eats cupcakes in one sitting, and each cupcake has a calorie count, . ...

[Lucky Algorithm] Ice Cream Parlor (51/77)

1 minute read

Ice Cream Parlor (Hacker Rank) Each time Sunny and Johnny take a trip to the Ice Cream Parlor, they pool together dollars for ice cream. On any given day, t...

[Lucky Algorithm] Picking Numbers (48/77)

less than 1 minute read

Picking Numbers (Hacker Rank) Given an array of integers, find and print the maximum number of integers you can select from the array such that the absolute ...

[Lucky Algorithm] Jim and the Orders (47/77)

less than 1 minute read

Jim and the Orders (Hacker Rank) Jim’s Burgers has hungry burger fans waiting in line. Each unique order, , is placed by a customer at time , and the order ...

[Lucky Algorithm] Missing Numbers (46/77)

less than 1 minute read

Missing Numbers (Hacker Rank) Numeros, the Artist, had two lists and , such that was a permutation of . Numeros was very proud of these lists. Unfortunatel...

[Codility Lessons] Flags(30/n)

less than 1 minute read

[Lesson10] Prime and composite numbers Flags : Find the maximum number of flags that can be set on mountain peaks.

[Codility Lessons] StoneWall(18/n)

less than 1 minute read

[Lesson7] Stacks and Queues StoneWall : Cover “Manhattan skyline” using the minimum number of rectangles Java Solution Link : https://codility.com/demo/res...

[Codility Lessons] Triangle(16/n)

less than 1 minute read

[Lesson6] Sorting Triangle : Determine whether a triangle can be built from a given set of edges. Java Solution

[Codility Lessons] Distinct(15/n)

less than 1 minute read

[Lesson6] Sorting Distinct : Compute number of distinct values in an array. Java Solution ``` import java.util.*;

[Codility Lessons] MinAvgTwoSlice(13/n)

less than 1 minute read

[Lesson5] Prefix Sums MinAvgTwoSlice : Find the minimal average of any slice containing at least two elements. Java Solution Task Score : 80 Correctness : ...

[Codility Lessons] PassingCars(12/n)

less than 1 minute read

[Lesson5] Prefix Sums PassingCars : Count the number of passing cars on the road. Java Solution Task Score : 90 Correctness : 100 Performance : 80 class S...

[Codility Lessons] MissingInteger(10/n)

1 minute read

[Lesson4] Counting Elements MaxCounters : Calculate the values of counters after applying all alternating operations: increase counter by 1; set value of all...

[Lucky Algorithm] Closest Number(43/77)

1 minute read

Closest Number (Hacker Rank) Sorting is often useful as the first step in many different tasks. The most common task is to make finding things easier, but th...

[Lucky Algorithm] Counting Sort 2(41/77)

1 minute read

Counting Sort 2 (Hacker Rank) Often, when a list is sorted, the elements being sorted are just keys to other values. For example, if you are sorting files by...

[Lucky Algorithm] Counting Sort 1(40/77)

1 minute read

Counting Sort 1 (Hacker Rank) Comparison Sorting Quicksort usually has a running time of , but is there an algorithm that can sort even faster? In general, t...

[Lucky Algorithm] The Power Sum(34/77)

less than 1 minute read

The Power Sum (Hacker Rank) Find the number of ways that a given integer, , can be expressed as the sum of the power of unique, natural numbers.

[Lucky Algorithm] Game of Stones(32/77)

less than 1 minute read

Game of Stones (Hacker Rank) Two players (numbered and ) are playing a game with stones. Player always plays first, and the two players move in alternatin...

[Lucky Algorithm] Pangrams(31/77)

less than 1 minute read

Pangrams (Hacker Rank) Roy wanted to increase his typing speed for programming contests. So, his friend advised him to type the sentence “The quick brown fox...

[Lucky Algorithm] Mars Exploration(29/77)

less than 1 minute read

Mars Exploration (Hacker Rank) Letters in some of the SOS messages are altered by cosmic radiation during transmission. Given the signal received by Earth as...

[Lucky Algorithm] CamelCase(28/77)

less than 1 minute read

CamelCase (Hacker Rank) Alice wrote a sequence of words in CamelCase as a string of letters, , having the following properties:

[Lucky Algorithm] Super Reduced String(27/77)

less than 1 minute read

Super Reduced String (Hacker Rank) Steve has a string, , consisting of lowercase English alphabetic letters. In one operation, he can delete any pair of adj...

[Lucky Algorithm] Find Digits(26/77)

less than 1 minute read

Find Digits (Hacker Rank) Given an integer, , traverse its digits (1,2,…,n) and determine how many digits evenly divide (i.e.: count the number of times di...

[Lucky Algorithm] The Hurdle Race(25/77)

less than 1 minute read

The Hurdle Race (Hacker Rank) Dan is playing a video game in which his character competes in a hurdle race by jumping over hurdles with heights . He can ini...

[Lucky Algorithm] Cats and a Mouse(24/77)

1 minute read

Cats and a Mouse (Hacker Rank) Two cats named and are standing at integral points on the x-axis. Cat is standing at point and cat is standing at point ....

[Lucky Algorithm] Electronics Shop (23/77)

1 minute read

Electronics Shop (Hacker Rank) Monica wants to buy exactly one keyboard and one USB drive from her favorite electronics store. The store sells different bra...

[Lucky Algorithm] Counting Valleys (22/77)

1 minute read

Counting Valleys (Hacker Rank) Gary is an avid hiker. He tracks his hikes meticulously, paying close attention to small details like topography. During his l...

[Lucky Algorithm] Drawing Book (21/77)

1 minute read

Drawing Book (Hacker Rank) Brie’s Drawing teacher asks her class to open their -page book to page number . Brie can either start turning pages from the front...

[Lucky Algorithm] Sock Merchant (19/77)

1 minute read

Sock Merchant (Hacker Rank) John’s clothing store has a pile of loose socks where each sock is labeled with an integer, , denoting its color. He wants to s...

[Lucky Algorithm] Bon Appétit (18/77)

1 minute read

Bon Appétit (Hacker Rank) Anna and Brian order items at a restaurant, but Anna declines to eat any of the item (where ) due to an allergy. When the check c...

[Lucky Algorithm] Migratory Birds (17/77)

1 minute read

Migratory Birds (Hacker Rank) A flock of birds is flying across the continent. Each bird has a type, and the different types are designated by the ID number...

[Lucky Algorithm] Between Two Sets (12/77)

1 minute read

Between Two Sets (Hacker Rank) Consider two sets of positive integers, and . We say that a positive integer, , is between sets and if the following condit...

[Lucky Algorithm] Kangaroo (11/77)

less than 1 minute read

Kangaroo (Hacker Rank) There are two kangaroos on a number line ready to jump in the positive direction (i.e, toward positive infinity). The first kangaroo s...

[Lucky Algorithm] Mini-Max Sum (6/77)

less than 1 minute read

Mini-Max Sum (Hacker Rank) Given five positive integers, find the minimum and maximum values that can be calculated by summing exactly four of the five integ...

[Lucky Algorithm] Staircase (5/77)

less than 1 minute read

Staircase (Hacker Rank) Consider a staircase of size : # ## ### #### Observe that its base and height are both equal to , and the image is dr...

[Lucky Algorithm] Plus Minus (4/77)

1 minute read

Plus Minus (Hacker Rank) Given an array of integers, calculate which fraction of its elements are positive, which fraction of its elements are negative, and ...

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