ProblemWe are required to write a JavaScript function that takes in the 1-based month index and return the quarter, which the month falls in.ExampleFollowing is the code − Live Democonst month = 7; const findQuarter = (month = 1) => {    if (month

ProblemWe are required to write a JavaScript function that takes in a number n and converts it to the corresponding string without using the inbuilt functions String() or toString() or using string concatenation.ExampleFollowing is the code − Live Democonst num = 235456; const convertToString = (num) => {    let res = '';    while(num){       res = (num % 10) + res;       num = Math.floor(num / 10);    };    return res; }; console.log(convertToString(num));OutputFollowing is the console output −235456

Doubleton NumberWe will call a natural number a "doubleton number" if it contains exactly two distinct digits. For example, 23, 35, 100, 12121 are doubleton numbers, and 123 and 9980 are not.ProblemWe are required to write a JavaScript function that takes in a number and return true if it is a doubleton number, false otherwise.ExampleFollowing is the code − Live Democonst num = 121212; const isDoubleTon = (num = 1) => {    const str = String(num);    const map = {};    for(let i = 0; i < str.length; i++){       const el = str[i];       ... Read More

ProblemWe are required to write a JavaScript function that takes in a string. Our function should convert every character of the string to the hex value of its ascii code, then the result should be the sum of the numbers in the hex strings ignoring the letters present in hex.ExampleFollowing is the code − Live Democonst str = "Hello, World!"; const toHexAndSum = (str = '') => {    return str    .split('')    .map(c=>c.charCodeAt())    .map(n=>n.toString(16))    .join('')    .split('')    .filter(c=>'123456789'.includes(c))    .map(d=>parseInt(d))    .reduce((a, b)=>a+b, 0) }; console.log(toHexAndSum(str));OutputFollowing is the console output −91Read More

Lucas NumbersLucas numbers are numbers in a sequence defined like this −L(0) = 2 L(1) = 1 L(n) = L(n-1) + L(n-2)ProblemWe are required to write a JavaScript function that takes in a number n and return the nth lucas number.ExampleFollowing is the code − Live Democonst num = 21; const lucas = (num = 1) => {    if (num === 0)       return 2;    if (num === 1)       return 1;    return lucas(num - 1) +       lucas(num - 2); }; console.log(lucas(num));OutputFollowing is the console output −24476

ProblemWe are required to write a JavaScript function that takes in an array of numbers, arr, as the first and the only argument.Our function should check whether the input array is a centrally peaked array or not. If it is a centrally peaked array, we should return true, false otherwise.The conditions for being a centrally peaked array are −arr.length >= 3There exists some i with 0 < i < arr.length - 1 such that:arr[0] < arr[1] < ... arr[i-1] < arr[i]arr[i] > arr[i+1] > ... > arr[arr.length - 1]For example, if the input to the function is −const arr = ... Read More

ProblemWe are required to write a JavaScript function that takes in an array of numbers, arr, as the first and the only argument.A move consists of choosing any arr[i], and incrementing it by 1. Our function is supposed to return the least number of moves to make every value in the array arr unique.For example, if the input to the function is −const arr = [12, 15, 7, 15];Then the output should be −const output = 1;Output ExplanationBecause if we increment any 15 to 16, the array will consist of all unique elements.ExampleThe code for this will be − Live Democonst ... Read More

ProblemJavaScript function that takes in two arrays, pushed and popped, as the first and the second argument. Both these arrays are guaranteed to consist of unique elements.Our function should return true if and only if this could have been the result of a sequence of push and pop operations on an initially empty stack, false otherwise.For example, if the input to the function is −const pushed = [1, 2, 3, 4, 5]; const popped = [4, 5, 3, 2, 1];Then the output should be −const output = true;Output ExplanationWe might do the following sequence −push(1), push(2), push(3), push(4), pop() -> ... Read More

ProblemWe are required to write a JavaScript function that takes in an array of numbers, arr, as the first and the only argument.The array arr, will always be of even length.Our function should return true if and only if it is possible to reorder it such that arr[2 * i + 1] = 2 * arr[2 * i] for every 0 {    const map = arr.reduce((acc, num) => {       acc[num] = (acc[num] || 0) + 1       return acc    }, {});    const keys = Object.keys(map)    .map(key => Number(key))    .sort((a, ... Read More

ProblemWe are required to write a JavaScript function that takes in an array of integers, arr, as the first and the only argument.Suppose two indices, i and j in the array which satisfy the following conditions −i < j, andarr[i] {    let max = 0    const stack = [0]    for (let i = 1; i < arr.length; i++) {       if (arr[i] < arr[stack[stack.length - 1]]) {          stack.push(i)       }    }    for (let i = arr.length - 1; i >= 0; i--) {       ... Read More