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A mathematical number defined in number theory in a given number base is a natural number equal to the perfect cube of another natural number such that the digit sum of the first natural number is equal to the digit sum of the second number(wikipedia).The number was found by Henry Dudeney. Its mathematical formula is −Here, we are given an integer n. Our task is to check whether the given number n is a dudeney number or not. Let’s take an example to understand the problem, Input: N = 17592Output: NoExplanation: The given number is not a dudney number.Solution Approach −The solution lies ... Read More
Every system works on operations mainly in two modes to safeguard hardware’s computation. The two modes are −User ModeKernel ModeUser Mode −The OS mode in which all the user applications and programs will run. Here, the user instructions are worked on and softwares like playing music is run.Kernel Mode −The OS mode in which the hardware loads and its computations are performed. Only privileged instructions are allowed to run in kernel mode. Some common privileged instructions are −Input-Output ManagementSwitching modes between user mode and kernel mode.Interrupt managementDual Mode in OS is the switching of modes between the two modes and switching of mode ... Read More
We are required to write a JavaScript function that takes in two strings of characters lets call them str1 and str2.The function should check whether we can form str2 from str1 by deleting exactly one character from str1. If we can do so the function should return true, false otherwise.For example −If the input strings are −const str1 = 'chemistty'; const str2 = 'chemisty';Then the output should be −const output = true;ExampleFollowing is the code −const str1 = 'chemistty'; const str2 = 'chemisty'; const stringSimilarity = (str1 = '', str2 = '') => { if(str1.length - str2.length !== 1){ ... Read More
We are required to write a JavaScript function that takes in an array of integers as the only argument.The function should sort the integers present in the array in increasing order based on the 1s present in their binary representation. If two or more numbers have the same number of 1s in their binary, they should be sorted in increasing order according to their magnitude.For example −If the input array is −const arr = [34, 37, 23, 89, 12, 31, 23, 89];Then the output array will be −const output = [34, 12, 37, 23, 89, 23, 89, 31];ExampleFollowing is the ... Read More
We are required to write a JavaScript function that takes in an array of literals as the first and the only argument.Our function should swap each consecutive even index with each other, and swap each consecutive odd indexes with each other.The function should do these swappings in place.For example −If the input array is −const arr = [0, 1, 2, 3, 4, 5, 6, 7, 8];Then the array should become −const output = [2, 3, 0, 1, 6, 7, 4, 5, 8];because 0 and 2 gets swapped, 1 and 3 gets swapped, 4 and 6 gets swapped, 5 and 7 ... Read More
We are required to write a JavaScript function that takes in an array of integers as the only argument.The function should check whether there exists an integer in the array such that its frequency is same as its value.If there exists at least one such integer, we should return that integer otherwise we should return -1.For example −If the input array is −const arr = [3, 4, 3, 8, 4, 9, 7, 4, 2, 4];Then the output should be −const output = 4;ExampleFollowing is the code −const arr = [3, 4, 3, 8, 4, 9, 7, 4, 2, 4]; const ... Read More
We are required to write a JavaScript function that takes in an array of integers as the only argument.The function should sort the array based on the following conditions −All even numbers are sorted in increasing orderAll odd numbers are sorted in decreasing orderThe relative positions of the even and odd numbers remain the sameFor example −If the input array is −const arr = [12, 17, 15, 24, 1, 6];Then the output should be −const output = [6, 17, 15, 12, 1, 24];ExampleFollowing is the code −const arr = [12, 17, 15, 24, 1, 6]; const specialSort = (nums = ... Read More
We are required to write a JavaScript function that takes in a number as the only argument.The function should check whether there exists any number whose factorial is the number taken as input.If there exists any such number, we should return that number otherwise we should return -1.For example −If the input is −const num = 720;Then the output should be −const output = 6;ExampleFollowing is the code −const num = 720; const checkForFactorial = num => { let prod = 1, count = 1; while(prod
We are required to write a JavaScript function that takes in an array of integers as the first and the only argument.The function should whether all the integers that are present in the array appear for unique number of times or not.If they do, the function should return true, false otherwise.For example −If the input array is −const arr = [7, 5, 5, 8, 2, 4, 7];Then the output should be −const output = false;because both the integers 7 and 5 appears for 2 times each.We will first use a hash map to map integers to their frequencies(occurrences) and then ... Read More
We are required to write a JavaScript function that takes in an array of integers as the first argument and a number, say n, as the second argument.The function should check whether there exists two such numbers in the array that one is the nth multiple of the other.If there exists any such pair in the array, the function should return true, false otherwise.For example −If the array and the number are −const arr = [4, 2, 7, 8, 3, 9, 5]; const n = 4;Then the output should be −const output = true;because there exist the numbers 2 and ... Read More