ProblemWe are required to write a JavaScript function that takes in number n. Our function should return the nth palindrome number if started counting from 0.For instance, the first palindrome will be 0, second will be 1, tenth will be 9, eleventh will be 11 as 10 is not a palindrome.ExampleFollowing is the code − Live Democonst num = 31; const findNthPalindrome = (num = 1) => {    const isPalindrome = (num = 1) => {       const reverse = +String(num)       .split('')       .reverse()       .join('');       return reverse === num;    };    let count = 0;    let i = 0;    while(count < num){       if(isPalindrome(i)){          count++;       };       i++;    };    return i - 1; }; console.log(findNthPalindrome(num));OutputFollowing is the console output −212

ProblemWe are required to write a JavaScript function that takes in a positive number n. We can do at most one operation −Choosing the index of a digit in the number, remove this digit at that index and insert it back to another or at the same place in the number in order to find the smallest number we can get.Our function should return this smallest number.ExampleFollowing is the code − Live Democonst num = 354166; const smallestShuffle = (num) => {    const arr = String(num).split('');    const { ind } = arr.reduce((acc, val, index) => {       ... Read More

Life Path NumberA person's Life Path Number is calculated by adding each individual number in that person's date of birth, until it is reduced to a single digit number.ProblemWe are required to write a JavaScript function that takes in a date in “yyyy-mm-dd” format and returns the life path number for that date of birth.For instance, if the date is: 1999-06-10year : 1 + 9 + 9 + 9 = 28 → 2 + 8 = 10 → 1 + 0 = 1 month : 0 + 6 = 6 day : 1 + 0 = 1 result: 1 + ... Read More

ProblemWe are required to write a JavaScript function that takes in two strings s1 and s2 including only letters from ato z.Our function should return a new sorted string, the longest possible, containing distinct letters - each taken only once - coming from s1 or s2.ExampleFollowing is the code − Live Democonst str1 = "xyaabbbccccdefww"; const str2 = "xxxxyyyyabklmopq"; const longestPossible = (str1 = '', str2 = '') => {    const combined = str1.concat(str2);    const lower = combined.toLowerCase();    const split =lower.split('');    const sorted = split.sort();    const res = [];    for(const el of sorted){     ... Read More

ProblemWe are required to design a data structure in JavaScript that supports the following two operations −addWord, which adds a word to that Data Structure (DS), we can take help of existing DS like arrays or any other DS to store this data, search, which searches a literal word or a regular expression string containing lowercase letters "a-z" or "." where "." can represent any letterFor exampleaddWord("sir") addWord("car") addWord("mad") search("hell") === false search(".ad") === true search("s..") === trueExampleFollowing is the code − Live Democlass MyData{    constructor(){       this.arr = [];    }; }; MyData.prototype.addWord = function (word) { ... Read More

ProblemWe are required to write a JavaScript function that takes in a number n. Our function should count and return the number of times we will have to use 9 while counting from 0 to n.ExampleFollowing is the code − Live Democonst num = 100; const countNine = (num = 0) => {    const countChar = (str = '', char = '') => {       return str       .split('')       .reduce((acc, val) => {          if(val === char){             acc++;          };          return acc;       }, 0);    };    let count = 0;    for(let i = 0; i

ProblemWe are required to write a JavaScript function that takes in a positive integer n written as abcd... (a, b, c, d... being digits) and a positive integer pwe want to find a positive integer k, if it exists, such as the sum of the digits of n taken to the successive powers of p is equal to k * n.In other words −Is there an integer k such as : (a ^ p + b ^ (p+1) + c ^(p+2) + d ^ (p+3) + ...) = n * kIf it is the case, we will return k, if ... Read More

ProblemWe are required to write a JavaScript function that takes in an array that represents the floor numbers at which a building lift stopped during an interval of time.From that data, our function should return the count of total number of floors covered by the lift in that time.ExampleFollowing is the code − Live Democonst arr = [7, 1, 7, 1]; const floorsCovered = (arr = []) => {    let res = 0;    for (let i = 0; i < arr.length; i++){       if (arr[i] > arr[i+1]){          res += arr[i] - arr[i+1];   ... Read More

ProblemWe are required to write a JavaScript function that takes in a decrypted message and returns its source message.All we know is the algorithm used to encrypt that message.And the algorithm is −Reverse the message string.Replace every letter with its ASCII code in quotes (A to '65', h to '104' and so on).Insert digits and spaces as is.ExampleFollowing is the code − Live Democonst str = '12 hello world 30'; const decryptString = (str = '') => {    const alpha = 'abcdefghijklmnopqrstuvwxyz';    let res = '';    for(let i = str.length - 1; i >= 0; i--){     ... Read More

ProblemWe are required to write a JavaScript function that takes in an array of exactly two subarrays with two numbers each.Both the subarrays represent a rational number in fractional form. Our function should add the rational numbers and return a new array of two numbers representing the simplest form of the added rational number.ExampleFollowing is the code − Live Democonst arr = [    [1, 2],    [1, 3] ]; const findSum = (arr = []) => {    const hcf = (a, b) => b ? hcf(b, a % b) : a;    if(!arr.length){       return null;   ... Read More