## Determine the Date by the Day Number in Java

The challenge What date corresponds to the nth day of the year?The answer depends on whether the year is a leap year or not. Write a function… Read More »Determine the Date by the Day Number in Java

The challenge What date corresponds to the nth day of the year?The answer depends on whether the year is a leap year or not. Write a function… Read More »Determine the Date by the Day Number in Java

The challenge You have to create a method, that corrects a given time string. There was a problem in addition, so many of the time… Read More »Correct the time-string in Java

The challenge You probably know that some characters written on a piece of paper, after turning this sheet 180 degrees, can be read, although sometimes… Read More »Shifter Words Challenge in Java

The challenge Make two functions, max and min that take a(n) array/vector of integers list as input and outputs, respectively, the largest and lowest number in that array/vector. Examples Additionally… Read More »Find Maximum and Minimum Values of a List in Java

The challenge Write a function that takes a string of parentheses, and determines if the order of the parentheses is valid. The function should return true if… Read More »Valid Parentheses in Java

The challenge Write a function that determines whether a string is a valid guess in a Boggle board, as per the rules of Boggle. A… Read More »Boggle Word Checker in Java

The challenge Your task is to construct a building which will be a pile of n cubes. The cube at the bottom will have a… Read More »Build a pile of Cubes in Kotlin

The challenge Consider the sequence U(n, x) = x + 2x**2 + 3x**3 + .. + nx**n where x is a real number and n a positive… Read More »Which x for that sum in Kotlin

The challenge Write a function that reverses the bits in an integer. For example, the number 417 is 110100001 in binary. Reversing the binary is 100001011 which is 267. You can assume… Read More »Reverse the bits in an integer in Java

The challenge Given a set of numbers, return the additive inverse of each. Each positive becomes negatives, and the negatives become positives. The solution in… Read More »Invert values in Kotlin

You have created a ./target/<app>.jar and have tried to run it using java -jar <app>.jar yet receive a spring boot no main manifest attribute, in… Read More »Spring Boot no main manifest attribute, in

The challenge A number system with moduli is deﬁned by a vector of k moduli, [m1,m2, ···,mk]. The moduli must be pairwise co-prime, which means that, for… Read More »Moduli number system in Kotlin

The challenge Given an array X of positive integers, its elements are to be transformed by running the following operation on them as many times… Read More »Smallest possible sum in Kotlin

The challenge Given a semi-inclusive interval I = [l, u) (l is in interval I but u is not) l and u being floating numbers (0 <= l < u), an integer n… Read More »Floating-point Approximation in Kotlin

The challenge Create an NxN multiplication table, of size provided in parameter. for example, when given size is 3: for given example, the return value should be: [[1,2,3],[2,4,6],[3,6,9]]… Read More »Multiplication table in Kotlin

The challenge Complete the solution so that it strips all text that follows any of a set of comment markers passed in. Any whitespace at… Read More »Strip Comments in Kotlin

The challenge Consider the sequence S(n, z) = (1 – z)(z + z**2 + z**3 + … + z**n) where z is a complex number and n a positive integer (n… Read More »Experimenting with a sequence of complex numbers in Kotlin

Percona has a great toolkit that allows you to perform schema changes on a MySQL or MariaDB database without any downtime, it works by creating… Read More »pt-online-schema-change Add Index

The challenge Let us consider this example (array written in general format): ls = [0, 1, 3, 6, 10] Its following parts: The corresponding sums… Read More »Sums of Parts in Kotlin

The challenge In mathematics, a Diophantine equation is a polynomial equation, usually with two or more unknowns, such that only the integer solutions are sought or studied.… Read More »Diophantine Equation in Kotlin

The challenge Write a function that accepts two square matrices (N x N two dimensional arrays), and return the sum of the two. Both matrices being… Read More »Matrix Addition in Java

The challenge The number 81 has a special property, a certain power of the sum of its digits is equal to 81 (nine squared). Eighty… Read More »Numbers that are a power of their sum of digits in Java

The challenge You have to give the number of different integer triangles with one angle of 120 degrees which perimeters are under or equal a… Read More »Integer triangles in Java

The challenge You’re given a square consisting of random numbers, like so: Your job is to calculate the minimum total cost when moving from the… Read More »Minimum path in squares in Java

The challenge Create a function that returns an array containing the first l digits from the nth diagonal of Pascal’s triangle. n = 0 should generate the first diagonal of… Read More »Pascal’s Diagonals in Java