Arrays and Container Classes

Let's start with an interview question.

A majority element is an element in array constitutes more than 50% of elements. For example, consider the numbers:

Here, the majority element is 99.

Challenge: Find the majority element in linear time using $O(1)$ memory.

Use Moore's voting algorithm.

C Arrays and Strings

C arrays and strings are useful to know for legacy codebases, but yo u should always use array<T> and vector<T> instead for projects.

Range-based for loops

In C++11, there are for-in loops. They are used like so:

for (auto x : array) { // use x }

If you want to change the values in array, use:

for (auto &x : array) { // change array values }

Container Classes

Objects that contain multiple data items, such as ints, doubles, or objects. They allow for control and protection over editing of objects, and can copy/edit/sort/order many objects at once.

They're also very combinable - you can have a vector of stacks.