Rotate array

This a problem set for you to work through

This is a problem set. Some of these are easy, others are far more difficult. The purpose of these problems sets are:

1. to build your skill applying computational thinking to a problem
2. to assess your knowledge and skills of different programming practices

What is this problem set trying to do

This is an actual interview question asked by facebook. You must understand two-dimensional lists and indices very, very well.

The Problem

This problem was asked by Facebook.

Given an N by N matrix, rotate it by 90 degrees clockwise.

For example, given the following matrix:

[[1, 2, 3],
 [4, 5, 6],
 [7, 8, 9]]

you should return:

[[7, 4, 1],
 [8, 5, 2],
 [9, 6, 3]]

How you will be assessed

Your solution will be graded using the following axis:

Scope

• To what extent does your code implement the features required by our specification?
• To what extent is there evidence of effort?

Correctness

• To what extent did your code meet specifications?
• To what extent did your code meet unit tests?
• To what extent is your code free of bugs?

Design

• To what extent is your code written well (i.e. clearly, efficiently, elegantly, and/or logically)?
• To what extent is your code eliminating repetition?
• To what extent is your code using functions appropriately?

Style

• To what extent is your code readable?
• To what extent is your code commented?
• To what extent are your variables well named?
• To what extent do you adhere to style guide?

A possible solution

Click the expand link to see one possible solution, but NOT before you have tried and failed!

not yet!

Consider the merits or otherwise of an argument or concept. Opinions and conclusions should be presented clearly and supported with appropriate evidence and sound argument.

Produce a plan, simulation or model.