Java

The Valid Mountain Array Problem using Java

Introducing the problem Given an array A of integers, return true if and only if it is a valid mountain array. Recall that A is a mountain array if and… Read More »The Valid Mountain Array Problem using Java

Find Numbers with Even Number of Digits using Java

The challenge Given an array nums of integers, return how many of them contain an even number of digits. Example 1: Input: nums = [12,345,2,6,7896] Output: 2 Explanation: 12… Read More »Find Numbers with Even Number of Digits using Java

How to use a Java HashSet by example

What is a HashSet A HashSet is an unordered collection containing unique elements. It has the standard collection operations Add, Remove, Contains, but since it… Read More »How to use a Java HashSet by example

The Decoded String at Index using Java

The Challenge An encoded string S is given.  To find and write the decoded string to a tape, the encoded string is read one character at a time and the following… Read More »The Decoded String at Index using Java

Find Maximum Subarrays using Java

The problem Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum. Example: Input:… Read More »Find Maximum Subarrays using Java

Finding Number Complements using Java

The problem Given a positive integer num, output its complement number. The complement strategy is to flip the bits of its binary representation. Example 1: Input: num =… Read More »Finding Number Complements using Java

Comparing Java and Javascript

Perhaps the first thing that most people ask when they hear the names of these two programming languages are. “Why do they have the same… Read More »Comparing Java and Javascript

The Primary Data Types in Java

In Java there are eight basic data types; which are: byte, short, int, long, float, double, boolean and char. It could realistically be said that… Read More »The Primary Data Types in Java

Comparing Objects in Java

TLDR; Java has a few different ways of comparing variables and objects with one another. ==, equals(), compareTo() and compare(). Java provides various operators such… Read More »Comparing Objects in Java