# Difference Of Squares

Find the difference between the square of the sum and the sum of the squares of the first N natural numbers.

The square of the sum of the first ten natural numbers is
(1 + 2 + ... + 10)² = 55² = 3025.

The sum of the squares of the first ten natural numbers is
1² + 2² + ... + 10² = 385.

Hence the difference between the square of the sum of the first
ten natural numbers and the sum of the squares of the first ten
natural numbers is 3025 - 385 = 2640.

## Setup

There are two different methods of getting set up to run the tests with Objective-C:

- Create an Xcode project with a test target which will run the tests.
- Use the ruby gem `objc` as a test runner utility.

Both are described in more detail here: http://exercism.io/languages/objective-c

### Submitting Exercises

When submitting an exercise, make sure your solution file is in the same directory as the test code.

The submit command will look something like:

```shell
exercism submit <path-to-exercism-workspace>/objective-c/difference-of-squares/DifferenceOfSquares.m
```

You can find the Exercism workspace by running `exercism debug` and looking for the line beginning
with Workspace.

## Source

Problem 6 at Project Euler [http://projecteuler.net/problem=6](http://projecteuler.net/problem=6)

## Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.