Programming Articles - Page 2166 of 3366

This class matches alpha numeric characters.Example  Live Demoimport java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class AlphanumericExample {    public static void main(String args[]) {       //Reading String from user       System.out.println("Enter a string");       Scanner sc = new Scanner(System.in);       String input = sc.nextLine();       //Regular expression       String regex = "[\p{Alnum}]";       //Compiling the regular expression       Pattern pattern = Pattern.compile(regex);       //Retrieving the matcher object       Matcher matcher = pattern.matcher(input);       int count = 0;     ... Read More

In this article, we will learn about the POSIX character classes p{Digit} Java regex. First, will know about \p{Digit} and the use of \p{Digit} along with examples. What is \p{Digit}? In Java regex, the \p{Digit} is a POSIX (Portable Operating System Interface) character class in Java regular expressions that matches any decimal digit character. This class matches decimal digits from 0 to 9.  The \p{Digit} is also equivalent to other expressions in Java: "\d": Follows the same POSIX standards. "[0-9]": For ASCII digits only. How to Use \p{Digit} in Java? We can use the ... Read More

Suppose we have an array of integers. We have to find the sum of the elements present from index i to j. Two things we have to keep in mind that the array will be immutable, so elements will not be altered, and there will be multiple such queries. So we have to care about the execution time for a large number of queries. Suppose the array is like A = [5, 8, 3, 6, 1, 2, 5], then if query is (A, 0, 3), then it will be 5 + 8 + 3 + 6 = 22.To solve this, ... Read More

Suppose we have an array to hold some numbers. There are non-zero values as well as zero values. So we have to send all zeros to the right without changing the relative order of other numbers. So if the array is like [0, 1, 5, 0, 3, 8, 0, 0, 9], then the final array will be [1, 5, 3, 8, 9, 0, 0, 0, 0]To solve this, we will follow these steps −Suppose index = 0for i = 0 to the length of Aif A[i] != 0, thenA[index] := A[i]index := index + 1for i = index to the ... Read More

Suppose we have a list of numbers from 0 to n. There is one number that is missing. We have to find the missing number in an efficient approach. So if A = [0, 1, 2, 3, 4, 5, 7, 8, 9], missing number is 6.To solve this, we will use the binary search approach.sort the list in ascending orderhigh = length of A, and low = 0while low < high, domid = low + (high – low)/2if A[mid] > midhigh = midotherwiselow = mid + 1return lowExampleLet us see the following implementation to get a better understanding − Live Democlass ... Read More

Ugly numbers are those numbers whose prime factors are 2, 3 or 5. From 1 to 15, there are 11 ugly numbers 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15. The numbers 7, 11, 13 are not ugly because they are prime. The number 14 is not ugly because in its prime factor the 7 will come. So suppose we want to check the 10th ugly number. The value will be 12.Let us see the following algorithm to get an idea −AlgorithmgetUglyNumbers(n)Input − The number of terms.Output − Find nth Ugly numbers.Begin    define array named uglyNum ... Read More

Anagrams are basically all permutations of a given string or pattern. This pattern searching algorithm is slightly different. In this case, not only the exact pattern is searched, it searches all possible arrangements of the given pattern in the text. So if the inputs are “ANAGRAM” and “NAAGARM”, then they are anagram, but “cat” and “fat” are not an anagramTo solve this, we will convert the string into a list of characters, then sort them, if two sorted lists are same then they are anagram.Example (Python)Let us see the following implementation to get a better understanding − Live Democlass Solution(object):   ... Read More

A linked list is a linear data structure where each element is a separate object, commonly referred to as a node. Each node contains two fields: the data and a pointer to the next node in the list. In this article, we'll learn how to delete a node from a singly linked list using Python. Suppose we have a linked list with a few elements. Our task is to delete a specific node, given only access to that node - not the head of the list. For example: Input: 1 → 3 → 5 → 7 → ... Read More

The Runnable interface is a functional interface defined in java.lang package. This interface contains a single abstract method, run() with no arguments. When an object of a class implementing this interface used to create a thread, then run() method has invoked in a thread that executes separately.Syntax@FunctionalInterface public interface Runnable {  void run(); }In the below example, we can implement a Runnable interface by using an anonymous class and lambda expression.Examplepublic class RunnableLambdaTest {    public static void main(String[] args) {       Runnable r1 = new Runnable() {          @Override          public void run() { // anonymous class   ... Read More

Suppose we have a number n. We have to check whether the number is the power of 2 or not. So is n = 16, then the output will be true, if n = 12, it will be false.To solve this we will use logical operations. If we see the numbers that are the power of two then in the binary representation of that number will be the MSb is 1, and all other bits are 0. So if we perform [n AND (n – 1)], this will return 0 if n is the power of 2. If we see ... Read More