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cpp/sieve/README.md

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+# Sieve
+
+Write a program that uses the Sieve of Eratosthenes to find all the primes from 2 up to a given number.
+
+The Sieve of Eratosthenes is a simple, ancient algorithm for finding all
+prime numbers up to any given limit. It does so by iteratively marking as
+composite (i.e. not prime) the multiples of each prime,
+starting with the multiples of 2.
+
+Create your range, starting at two and continuing up to and including the given limit. (i.e. [2, limit])
+
+The algorithm consists of repeating the following over and over:
+
+- take the next available unmarked number in your list (it is prime)
+- mark all the multiples of that number (they are not prime)
+
+Repeat until you have processed each number in your range.
+
+When the algorithm terminates, all the numbers in the list that have not
+been marked are prime.
+
+The wikipedia article has a useful graphic that explains the algorithm:
+https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
+
+Notice that this is a very specific algorithm, and the tests don't check
+that you've implemented the algorithm, only that you've come up with the
+correct list of primes.
+
+## Getting Started
+
+Make sure you have read the [getting started with C++](http://help.exercism.io/getting-started-with-cpp.html)
+page on the [exercism help site](http://help.exercism.io/).  This covers
+the basic information on setting up the development environment expected
+by the exercises.
+
+## Passing the Tests
+
+Get the first test compiling, linking and passing by following the [three
+rules of test-driven development](http://butunclebob.com/ArticleS.UncleBob.TheThreeRulesOfTdd).
+Create just enough structure by declaring namespaces, functions, classes,
+etc., to satisfy any compiler errors and get the test to fail.  Then write
+just enough code to get the test to pass.  Once you've done that,
+uncomment the next test by moving the following line past the next test.
+
+```C++
+#if defined(EXERCISM_RUN_ALL_TESTS)
+```
+
+This may result in compile errors as new constructs may be invoked that
+you haven't yet declared or defined.  Again, fix the compile errors minimally
+to get a failing test, then change the code minimally to pass the test,
+refactor your implementation for readability and expressiveness and then
+go on to the next test.
+
+Try to use standard C++11 facilities in preference to writing your own
+low-level algorithms or facilities by hand.  [CppReference](http://en.cppreference.com/)
+is a wiki reference to the C++ language and standard library.  If you
+are new to C++, but have programmed in C, beware of
+[C traps and pitfalls](http://www.slideshare.net/LegalizeAdulthood/c-traps-and-pitfalls-for-c-programmers).
+
+## Source
+
+Sieve of Eratosthenes at Wikipedia [view source](http://en.wikipedia.org/wiki/Sieve_of_Eratosthenes)