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In this article, we will discuss different approaches to calculate the number of positive integers which have no repeated digits between a given range Low to high. The first approach is a brute force approach which iterates over all the numbers in the range and check if they contain repeated digits. In our second approach, we calculated the desired count using prefix array while in our last approach we used the concept of memorization in dynamic programming to get the desired result. Problem Statement: We are given two numbers low and high and we have to find the count of ... Read More
In this article, we will discuss what is Tomohiko Sakamoto’s algorithm and how this algorithm is used to identify which day of the week does the given date occurs. There are multiple algorithms to know the day of the week but this algorithm is the most powerful one. This algorithm finds the day of the month on which the date occurs in least possible time and least space complexity. Problem statement − We are given a date as per Georgian calendar and our task is to find out which day of the week occurs on the given date using ... Read More
In this article, we will discuss a few recursive practice problems with their detailed solutions. Let us first understand what recursion is and how it works: Recursion − Recursion is a programming technique in which a function or method calls itself multiple times in order to solve a problem. The function breaks down the problem into smaller sub-problems and solves them until it reaches a base case. The base case is a stopping condition that makes sure that the function stops calling itself and returns a result in finite time. Recursion is a powerful technique for solving complex ... Read More
In this article, we will discuss the code solution to swap every alternate bit in a given number and return the resultant number. We will use the concept of bit manipulation in order to solve the problem in constant time without using any loops. Problem statement − We are given a number n, we have to swap the pair of bits that are adjacent to each other. In other words, we have to swap every odd placed bit with its adjacent even placed bit. Constrain: While solving the problem, we have to keep In mind that we cannot use ... Read More
In this article, we will study different approaches to calculate the sum of the series- (n^2 - 1^2) + 2(n^2 - 2^2) + …. n(n^2 - n^2). In the first approach, we will calculate the series sum one by one for each i in the range 1 to n and keep adding it to the final sum. In the second approach, we will derive a mathematical formula to calculate the sum of the given series which will result in the reduced time complexity of the program from O(n) to O(1). Problem statement − We are given a number “n “and ... Read More
Collections in Java is a framework which provides classes and interfaces to manipulate group of objects. Collections help in storing and manipulating different types of objects in java. Size of the collection tells us how many elements are present in that particular collection. Java provides various collection classes namely ArrayList, LinkedList, HashSet, and TreeSet, among others. In this section, we are going to write a java program to get the size of collection and verify the collection is empty or not. The different types of collections in Java are − List − List is an ordered collection of objects ... Read More
Last Modification Date of a File refers to the last date on which the file data is edited. We have various functions in java to find the last modification date of a file. In this section, we will be discussing different approaches of implementing a java program to get the last modification date of a file. File is a collection of information which may contain data such as text information, images, audio, videos, program code. These can be accessed by any software applications to perform actions like read, write, update, delete etc. We will now look in to each function ... Read More
In this problem statement we have to find the largest difference between elements with a twist with the help of Javascript functionalities. So we will use basic Javascript to get the desired result. Understanding the problem The problem at hand is to find the largest difference between two items in an array. So we will add a twist to the problem. So we will not simply find the difference between two items but we will find the largest difference between an item and any smaller item that has appeared before in the array. And we will not rearrange ... Read More
In this problem statement, our task is to write the function for getting the total subarrays with sum K with the help of Javascript. So for doing this task we will use basic functionality of Javascript. Understanding the problem statement The problem statement is to create a function which will take an array of integers and a target sum K. So after processing the calculation it will return the total number of subarrays in the array with a sum of K. A subarray can be defined as a continuous series of items in the array. For example suppose ... Read More
Our goal in the above problem statement is to use Javascript functionalities and determine whether or not the given arrays are subsets of each other. So using loops we can fix this problem. Understanding the problem The problem description specifies that we have to identify that the given array is a subset of another array. Or we have to check that all of the items in the second array are present in the first array. For example, suppose we have an array like ['a', 'b', 'c', 'd', 'e'] and a second array ['b', 'd', 'e']. So when we ... Read More