63 lines
2.4 KiB
Markdown
63 lines
2.4 KiB
Markdown
# Nucleotide Count
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Given a DNA string, compute how many times each nucleotide occurs in the string.
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DNA is represented by an alphabet of the following symbols: 'A', 'C',
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'G', and 'T'.
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Each symbol represents a nucleotide, which is a fancy name for the
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particular molecules that happen to make up a large part of DNA.
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Shortest intro to biochemistry EVAR:
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- twigs are to birds nests as
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- nucleotides are to DNA and RNA as
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- amino acids are to proteins as
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- sugar is to starch as
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- oh crap lipids
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I'm not going to talk about lipids because they're crazy complex.
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So back to nucleotides.
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DNA contains four types of them: adenine (`A`), cytosine (`C`), guanine
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(`G`), and thymine (`T`).
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RNA contains a slightly different set of nucleotides, but we don't care
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about that for now.
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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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The Calculating DNA Nucleotides_problem at Rosalind [view source](http://rosalind.info/problems/dna/)
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