You are given an unordered array consisting of consecutive integers [1, 2, 3, ..., n] without any duplicates. You are allowed to swap any two elements. You need to find the minimum number of swaps required to sort the…
Comparators are used to compare two objects. In this challenge, you'll create a comparator and use it to sort an array. The Player class is provided in the editor below. It has two fields: : a string. : an integer…
You are given an array and you need to find number of triplets of indices such that the elements at those indices are in geometric progression for a given common ratio and . For example, . If , we have and at indices…
There are groups of friends, and each group is numbered from 1 to . The th group contains people. They live near a bus stop, and only a single bus operates on this route. An empty bus arrives at the bus stop and all the…
Jim enters a candy shop which has N different types of candies, each candy is of the same price. Jim has enough money to buy K candies. In how many different ways can he purchase K candies if there are infinite candies…
On the eve of Diwali, Hari is decorating his house with a serial light bulb set. The serial light bulb set has N bulbs placed sequentially on a string which is programmed to change patterns every second. If at least one…
You are given an integer, . Write a program to determine if is an element of the Fibonacci sequence. The first few elements of the Fibonacci sequence are . A Fibonacci sequence is one where every element is a sum of the…
You are given an integer N. Can you find the least positive integer X made up of only 9's and 0's, such that, X is a multiple of N? Update X is made up of one or more occurences of 9 and zero or more occurences of 0…
Kristen loves playing with and comparing numbers. She thinks that if she takes two different positive numbers, the one whose digits sum to a larger number is better than the other. If the sum of digits is equal for both…
Akash and Akhil are playing a game. They have balls numbered from to . Akhil asks Akash to reverse the position of the balls, i.e., to change the order from say, 0,1,2,3 to 3,2,1,0. He further asks Akash to reverse the…
A group of friends want to buy a bouquet of flowers. The florist wants to maximize his number of new customers and the money he makes. To do this, he decides he'll multiply the price of each flower by the number of that…
Goodland is a country with a number of evenly spaced cities along a line. The distance between adjacent cities is unit. There is an energy infrastructure project planning meeting, and the government needs to know the…
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 unfairness is minimized. Call that array . Unfairness of an array is calculated as Where…
The member states of the UN are planning to send people to the moon. They want them to be from different countries. You will be given a list of pairs of astronaut ID's. Each pair is made of astronauts from the same…
You are given a 2D matrix of dimension and a positive integer . You have to rotate the matrix times and print the resultant matrix. Rotation should be in anti-clockwise direction. Rotation of a matrix is represented by…
A gene is represented as a string of length (where is divisible by ), composed of the letters , , , and . It is considered to be steady if each of the four letters occurs exactly times. For example, and are both steady…
Given an array of integers, determine whether the array can be sorted in ascending order using only one of the following operations one time. Swap two elements. Reverse one sub-segment. Determine whether one, both or…
Given a 2D array of digits or grid, try to find the occurrence of a given 2D pattern of digits. For example, consider the following grid: Assume we need to look for the following 2D pattern array: The 2D pattern begins…
Alice is playing an arcade game and wants to climb to the top of the leaderboard and wants to track her ranking. The game uses Dense Ranking, so its leaderboard works like this: The player with the highest score is…
Sherlock considers a string to be valid if all characters of the string appear the same number of times. It is also valid if he can remove just character at index in the string, and the remaining characters will occur…
