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Articles on Trending Technologies
Technical articles with clear explanations and examples
How to Control Test Execution Order in TestNG?
A TestNG class can have different tests like test1, test2, test3 etc. Once a user runs the TestNG class consisting of various tests, it runs the test cases in alphabetically order based on the name provided. However, user can assign the priority to these tests so that these tests can run as per user’s priority. Priority starts from 0 and be in incremental order. Priority 0 takes the highest priority and decreasing the priority when priority gets increase as 1, 2, 3 etc. In this article, let’s analyse how to control the order of execution in different ways. Scenario 1 ...
Read MoreCheck If a Particular File System is Open or Not in Java
In Java, a file system is a hierarchical structure used to organize and store files and directories on a storage device. It provides a standard way to access and manipulate files and directories, regardless of the underlying storage device, such as a hard disk, USB drive, or cloud storage. Java provides the java.nio.file package, which contains classes and interfaces for working with file systems. The FileSystem interface represents a file system, and its FileSystems class provides factory methods for creating instances of FileSystem. You can check if a particular file system is open or not by using the FileSystem ...
Read MoreToggle First and Last Bits of a Number
The following article provides an in depth explanation of the method used to modify a number by toggling its first and last bit using bitwise operators. A bitwise operator is an operator that can be used to manipulate individual bits in binary numbers or bit patterns. Problem Statement For a given number n, modify the number such that the first and the last bit of the binary expansion of the new number are flipped i.e. if the original bit is 1 then the flipped bit should be 0 and vice versa. All the bits between the first and the last ...
Read MoreThe Sum of the Fifth Powers of the First n Natural Numbers
Natural numbers are numbers that start from 1 and include all the positive integers. The following article discusses two possible approaches to compute the sum of the fifth powers of the first n natural numbers. The article discusses the two approaches in detail and compares them with regards to efficiency and intuitiveness. Problem Statement The purpose of this problem is to compute the arithmetic sum of the first n natural numbers, all raised to their fifth power i.e. $\mathrm{1^5 + 2^5 + 3^5 + 4^5 + 5^5 + … + n^5}$ till the nth term. Examples Since n is a ...
Read MorePernicious Number
A number is considered to be pernicious if the number is a positive integer and the number of set bits in its binary expansion are prime. The first pernicious number is 3, as 3 = (11)2. It can be seen that the number of set bits in the binary representation of 3 are 2, which is a prime number. The first 10 pernicious numbers are 3, 5, 6, 7, 9, 10, 11, 12, 13, 14. Interestingly, powers of 2 can never be pernicious since they always have only 1 set bit. 1 is not a prime number. On the other ...
Read MoreOdious Number
A number is considered to be an odious number if it has an odd number of 1s in its binary expansion. The first 10 odious numbers are 1, 2, 4, 7, 10, 11, 13, 14, 16, 19, 21. Interestingly, all powers of 2 are odious since they have only 1 set bit. The following article discusses 2 approaches in detail to find whether a number is an odious number or not. Problem Statement This problem aims to check whether the given number is an odious number i.e. it is a positive number with an odd number of set bits in ...
Read MoreFind Last Palindrome String in the given Array
In this problem, we need to find the last palindrome string in the array. If any string is the same in reading, either we start to read from the start or end, we can say the string is a palindrome. We can compare the starting and ending characters to check whether the particular string is palindromic. Another way to find the palindromic string is to reverse the string and compare it with the original string. Problem statement – We have given an array of length N containing the different strings. We need to find the last palindrome string in the ...
Read MoreFind any permutation of Binary String of given size not present in Array
In this problem, we need to find all missing binary strings of length N from the array. We can solve the problem by finding all permutations of a binary string of length N and checking which permutations are absent in the array. Here, we will see iterative and recursive approaches to solve the problem. Problem statement – We have given an array arr[] of different lengths containing the binary strings of length N. We need to find all the missing binary strings of length N from the array. Sample examples Input – arr = {"111", "001", "100", "110"}, N = ...
Read MoreCount of substrings containing exactly K distinct vowels
In this problem, we need to count the total number of substrings of string str containing exactly K distinct vowels. We can solve the problem in two different ways. The first approach is to traverse all substrings and count the number of vowels in each substring. We can also use the map data structure to optimize the code of the first approach. Problem statement – We have given string str of length N. The string contains uppercase and lowercase alphabetical characters. Also, we have given integer K. We need to find the total number of substrings of str containing exactly ...
Read MoreCount of K length substrings containing exactly X vowels
In this problem, we need to find a total number of substrings of length K containing exactly K vowels. We will see two different approaches to solving the problem. We can use a naïve approach that checks the number of vowels in each substring of length K. Also, we can use the sliding window approach to solve the problem. Problem statement – We have given a string str of length N containing lowercase and uppercase alphabetical characters. We need to count the total number of substrings of length K which contains exactly X vowels. Sample examples Input– str = ...
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