52 lines
2.1 KiB
Markdown
52 lines
2.1 KiB
Markdown
# Difference Of Squares
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Find the difference between the sum of the squares and the square of the sums of the first N natural numbers.
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The square of the sum of the first ten natural numbers is,
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(1 + 2 + ... + 10)**2 = 55**2 = 3025
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The sum of the squares of the first ten natural numbers is,
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1**2 + 2**2 + ... + 10**2 = 385
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Hence the difference between the square of the sum of the first
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ten natural numbers and the sum of the squares is 2640:
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3025 - 385 = 2640
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## Getting Started
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Make sure you have read the [getting started with C++](http://help.exercism.io/getting-started-with-cpp.html)
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page on the [exercism help site](http://help.exercism.io/). This covers
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the basic information on setting up the development environment expected
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by the exercises.
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## Passing the Tests
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Get the first test compiling, linking and passing by following the [three
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rules of test-driven development](http://butunclebob.com/ArticleS.UncleBob.TheThreeRulesOfTdd).
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Create just enough structure by declaring namespaces, functions, classes,
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etc., to satisfy any compiler errors and get the test to fail. Then write
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just enough code to get the test to pass. Once you've done that,
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uncomment the next test by moving the following line past the next test.
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```C++
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#if defined(EXERCISM_RUN_ALL_TESTS)
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```
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This may result in compile errors as new constructs may be invoked that
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you haven't yet declared or defined. Again, fix the compile errors minimally
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to get a failing test, then change the code minimally to pass the test,
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refactor your implementation for readability and expressiveness and then
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go on to the next test.
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Try to use standard C++11 facilities in preference to writing your own
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low-level algorithms or facilities by hand. [CppReference](http://en.cppreference.com/)
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is a wiki reference to the C++ language and standard library. If you
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are new to C++, but have programmed in C, beware of
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[C traps and pitfalls](http://www.slideshare.net/LegalizeAdulthood/c-traps-and-pitfalls-for-c-programmers).
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## Source
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Problem 6 at Project Euler [view source](http://projecteuler.net/problem=6)
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