Java

First Variation on Caesar Cipher in Java

January 11, 2021 #Java

The challenge

The action of a Caesar cipher is to replace each plaintext letter (plaintext letters are from ‘a’ to ‘z’ or from ‘A’ …

Century From Year in Java

January 10, 2021 #Java

The challenge

The first century spans from the year 1 up to and including the year 100, The second – from the year 101 up to and including the year …

Find the Smallest Number in Java

January 9, 2021 #Java

The challenge

You have a positive number n consisting of digits. You can do at most one operation: Choosing the index of a digit in the number, remove …

Convert Array to Tree in Java

January 8, 2021 #Java

The challenge

You are given a non-null array of integers. Implement the method arrayToTree which creates a binary tree from its values in accordance …

Common Denominators in Java

January 7, 2021 #Java

The challenge

You will have a list of rationals in the form

{ {numer_1, denom_1} , ... {numer_n, denom_n} } 
or
[ [numer_1, denom_1] , ... [numer_n, …

Primes in Numbers in Java

January 6, 2021 #Java

The challenge

Given a positive number n > 1 find the prime factor decomposition of n. The result will be a string with the following form : …

Maximum subarray sum in Java

January 5, 2021 #Java

The challenge

The maximum sum subarray problem consists in finding the maximum sum of a contiguous subsequence in an array or list of integers: …

Validate Credit Card Number in Java

January 4, 2021 #Java

The challenge

Let’s implement the Luhn Algorithm, which is used to help validate credit card numbers.

Given a positive integer of up to 16 …

Find the unique number using Java

January 3, 2021 #Java

The challenge

There is an array with some numbers. All numbers are equal except for one. Try to find it!

Solution.findUniq(new double[]{ 1, 1, 1, 2, …

Find The Parity Outlier in Java

January 2, 2021 #Java

The challenge

You are given an array (which will have a length of at least 3, but could be very large) containing integers. The array is either …

Find the missing letter using Java

January 1, 2021 #Java

The challenge

Write a method that takes an array of consecutive (increasing) letters as input and that returns the missing letter in the array.

You …

Determine the order of braces is valid using Java

December 31, 2020 #Java

The challenge

Write a function that takes a string of braces, and determines if the order of the braces is valid. It should return true if the string …