# Blogs Hub

### by Sumit Chourasia | May 22, 2021 coding

#### Install and Configure MongoDB on Ubuntu - GeetCode

Prerequisites<br />Ubuntu Server 18.04 - 64 bit<br />Root privileges<br />What we will do in this tutorial: Install MongoDB<br />Configure MongoDB<br />Conclusion<br />Install MongoDB on Ubuntu 18.04 LTS<br />Step 1 - Importing the Public Key<br />GPG keys of the software distributor are r

### by Sumit Chourasia | Mar 31, 2021 coding

#### Minimum Changes To Make Alternating Binary String - String - Easy - LeetCode - GeetCode

You are given a string s consisting only of the characters '0' and '1'. In one operation, you can change any '0' to '1' or vice versa. The string is called alternating if no two adjacent characters are equal. For example, the string "010" is alternating, while the string "0100" is not.

### by Sumit Chourasia | Mar 31, 2021 coding

#### Check if Array Is Sorted and Rotated - Array - Easy - LeetCode - GeetCode

Given an array nums, return true if the array was originally sorted in non-decreasing order, then rotated some number of positions (including zero). Otherwise, return false. There may be duplicates in the original array. Note: An array A rotated by x positions results in an array B

### by Sumit Chourasia | Mar 04, 2021 coding

#### Maximum Swap - Array - Medium - LeetCode - GeetCode

Given a non-negative integer, you could swap two digits at most once to get the maximum valued number. Return the maximum valued number you could get. Example 1:<br />Input: 2736<br />Output: 7236<br />Explanation: Swap the number 2 and the number 7.<br />Example 2:<br />Input: 9973<br />O

### by Sumit Chourasia | Feb 13, 2021 coding

#### Sum of Unique Elements - Array - Easy - LeetCode - GeetCode

You are given an integer array nums. The unique elements of an array are the elements that appear exactly once in the array. Return the sum of all the unique elements of nums. &nbsp; Example 1: Input: nums = [1,2,3,2]<br />Output: 4<br />Explanation: The unique element

### by Sumit Chourasia | Feb 13, 2021 coding

#### Maximum Number of Balls in a Box - Maths - Easy - LeetCode - GeetCode

You are working in a ball factory where you have n balls numbered from lowLimit up to highLimit inclusive (i.e., n == highLimit - lowLimit + 1), and an infinite number of boxes numbered from 1 to infinity. Your job at this factory is to put each ball in the box with a number equal to the s

### by Sumit Chourasia | Jan 26, 2021 coding

#### Beautiful Arrangement II - Maths - Medium - LeetCode - GeetCode

Given two integers n and k, you need to construct a list that contains n different positive integers ranging from 1 to n and obeys the following requirement:<br />Suppose this list is [a1, a2, a3, ... , an], then the list [|a1 - a2|, |a2 - a3|, |a3 - a4|, ... , |an-1 - an|] has exactly k distinct

### by Sumit Chourasia | Jan 26, 2021 coding

#### Latest Time by Replacing Hidden Digits - String - Easy - LeetCode - GeetCode

You are given a string time in the form of hh:mm, where some of the digits in the string are hidden (represented by ?). The valid times are those inclusively between 00:00 and 23:59. Return the latest valid time you can get from time by replacing the hidden digits. &nbsp;

### by Sumit Chourasia | Jan 26, 2021 coding

#### Find the Highest Altitude - Array - Easy - LeetCode - GeetCode

There is a biker going on a road trip. The road trip consists of n + 1 points at different altitudes. The biker starts his trip on point 0 with altitude equal 0. You are given an integer array gain of length n where gain[i] is the net gain in altitude between points i​​​​​​ and i + 1 for a

### by Sumit Chourasia | Jan 18, 2021 coding

#### Number Of Rectangles That Can Form The Largest Square - Array - Easy - LeetCode - GeetCode

You are given an array rectangles where rectangles[i] = [li, wi] represents the ith rectangle of length li and width wi. You can cut the ith rectangle to form a square with a side length of k if both k &lt;= li and k &lt;= wi. For example, if you have a rectangle [4,6], you can cut it to g

### by Sumit Chourasia | Jan 10, 2021 coding

#### Decode XORed Array - Array - Easy - LeetCode - GeetCode

There is a hidden integer array arr that consists of n non-negative integers. It was encoded into another integer array encoded of length n - 1, such that encoded[i] = arr[i] XOR arr[i + 1]. For example, if arr = [1,0,2,1], then encoded = [1,2,3]. You are given the encoded array. Yo