C/C++ Coding Exercise – Find Two Single Numbers
Given an array of numbers nums, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the two elements that appear only …
How to Delete Node in a Linked List (Given Only Access to That Node)?
Write a function to delete a node (except the tail) in a singly linked list, given only access to that node. Supposed the linked list is 1 -> 2 …
How to Invert a Binary Tree in C/C++?
This problem was inspired by this original tweet by Max Howell: Google: 90% of our engineers use the software you wrote (Homebrew), but you can’t invert a binary tree …
C++ Coding Exercise – Self Crossing
You are given an array x of n positive numbers. You start at point (0,0) and moves x metres to the north, then x metres to the west, x …
C++ Coding Exercise – Palindrome Pairs
This is classified as a hard puzzle: https://leetcode.com/problems/palindrome-pairs/ A palindrome string is a string whose reverse string is exactly the same, e.g. ABBA, 1, UIU… Brute Force Almost every …
SQL Coding Exercise – Find Department Highest Salary
Submit your solution: https://leetcode.com/problems/department-highest-salary/ As seen, two tables, you are asked to list the highest salary for each department and the employee name. However, if there are two or …