Javascript Articles - Page 188 of 534

Interpolation SearchInterpolation search is an algorithm for searching for a key in an array that has been ordered by numerical values assigned to the keys (key values).For exampleSuppose, we have a sorted array of n uniformly distributed values arr[], and we need to write a function to search for a particular element target in the array.It does the following operations to find the position −// The idea of the formula is to return a higher value of pos// when element to be searched is closer to arr[hi]. And// smaller value when closer to arr[lo]pos = lo + ((x - arr[lo]) ... Read More

Levenshtein DistanceThe Levenshtein distance is a string metric for measuring the difference between two sequences. It is the minimum number of single-character edits required to change one word into the other.For example −Consider, we have these two strings −const str1 = 'hitting'; const str2 = 'kitten';The Levenshtein distance between these two strings is 3 because we are required to make these three edits −kitten → hitten (substitution of "h" for "k")hitten → hittin (substitution of "i" for "e")hittin → hitting (insertion of "g" at the end)We are required to write a JavaScript function that takes in two strings and calculates ... Read More

The power set of a set S is the set of all of the subsets of S, including the empty set and S itself. The power set of set S is denoted as P(S).For exampleIf S = {x, y, z}, the subsets are −{    {},    {x},    {y},    {z},    {x, y},    {x, z},    {y, z},    {x, y, z} }We are required to write a JavaScript function that takes in an array as the only argument. The function should find and return the power set for the input array.ExampleFollowing is the code −const set ... Read More

RadianThe radian is the unit for measuring angles and is the standard unit of angular measure used in many areas of mathematics.We are required to write a JavaScript function that takes in a number that represents some degree and returns its corresponding radian.ExampleFollowing is the code −const deg = 180; const degreeToRadian = (degree) => {    const factor = (Math.PI / 180);    const rad = degree / factor;    return rad; }; console.log(degreeToRadian(deg));OutputFollowing is the output on console −10313.240312354817

Suppose we have the following problem −There are n stairs, a person standing at the bottom wants to reach the top. The person can climb either 1 or 2 stairs at a time. We are required to count the number of ways, the person can reach the top.We are required to write a JavaScript function that takes in a number n that denotes the number of stairs. The function should count and return the number of ways in which the stairs can be climbed.ExampleFollowing is the code −const recursiveStaircase = (num = 10) => {    if (num

Block SearchJust like Binary Search, Block Search is also a searching algorithm for sorted arrays. The basic idea is to check fewer elements (than linear search) by jumping ahead by fixed steps or skipping some elements in place of searching all elements.For exampleSuppose we have an array arr of length n and block (to be jumped) of size m. Then we search at the indexes arr[0], arr[m], arr[2 * m], ..., arr[k * m] and so on.Once we find the interval arr[k * m] < x < arr[(k+1) * m], we perform a linear search operation from the index k ... Read More

Cartesian Product Inset theory a Cartesian product is a mathematical operation that returns a set (or product set or simply product) from multiple sets.That is, for sets A and B, the Cartesian product A × B is the set of all ordered pairs (a, b) where a ∈ A and b ∈ B.We are required to write a JavaScript function that takes in two arrays let us call them arr1 and arr2, they both represent two distinct sets.The function should construct a 2-D array that contains the cartesian product of those two sets and finally return that array.ExampleFollowing is the code ... Read More

Suppose we are given a set of candidate numbers (without duplicates) and a target number (target).We are required to write a function that finds all unique combinations in candidates where the candidate numbers sum to the target.The same repeated number may be chosen from candidates an unlimited number of times.Note −All numbers (including target) will be positive integers.The solution set must not contain duplicate combinations.For example −If the inputs are −candidates = [2, 3, 6, 7], target = 7, The solution to this can be −[    [7],    [2, 2, 3] ];Since the problem is to get all the ... Read More

Suppose we are given an input string str and a pattern p, we are required to implement regular expression matching with support for. and *.The functions of these symbols should be −. --> Matches any single character.* --> Matches zero or more of the preceding elements.The matching should cover the entire input string (not partial).Notestr could be empty and contains only lowercase letters a-z.p could be empty and contains only lowercase letters a-z, and characters like. or *.For example −If the input is −const str = 'aa'; const p = 'a';Then the output should be false because a does not ... Read More

We are required to write a JavaScript function that takes in a number and determines whether or not it is a power of two.For example −f(23) = false f(16) = true f(1) = true f(1024) = trueApproach −Powers of two in binary form always have just one bit. Like this −1: 0001 2: 0010 4: 0100 8: 1000Therefore, after checking that the number is greater than zero, we can use a bitwise hack to test that one and only one bit is set. The same is shown below −num & (num - 1)ExampleFollowing is the code −const num1 = 256; ... Read More