December 2020 – Let us code

Employee couples – SQL Puzzle

December 22, 2020adminLeave a comment

Given a table schema of employees like the following. Employee id, employee name, and spouse id if their spouse is also working in the same company. spouse id will be null if only one person is working. Id Name Spouse id 100 Sachin 101 101 Anjali 100 102 Virat 103 103 Anushka 102 104 Sanju…

Finding the first missing positive integer

December 7, 2020adminLeave a comment

Given an array of numbers, find the first missing positive number. The array may contain both positive, negative numbers in any order. For example, consider the following input/outputs. Input: [8, -5, 0, 1, 4, 3]Output: 2Input: [4, 3, 1, 5, 2]Output: 6Input: [-3, -6, 0, 2, 5, 6]Output: 1 One simple algorithm is to…