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Diffstat (limited to 'samples/prime_tables.h')
-rw-r--r-- | samples/prime_tables.h | 123 |
1 files changed, 0 insertions, 123 deletions
diff --git a/samples/prime_tables.h b/samples/prime_tables.h deleted file mode 100644 index 92ce16a..0000000 --- a/samples/prime_tables.h +++ /dev/null @@ -1,123 +0,0 @@ -// Copyright 2008 Google Inc. -// All Rights Reserved. -// -// Redistribution and use in source and binary forms, with or without -// modification, are permitted provided that the following conditions are -// met: -// -// * Redistributions of source code must retain the above copyright -// notice, this list of conditions and the following disclaimer. -// * Redistributions in binary form must reproduce the above -// copyright notice, this list of conditions and the following disclaimer -// in the documentation and/or other materials provided with the -// distribution. -// * Neither the name of Google Inc. nor the names of its -// contributors may be used to endorse or promote products derived from -// this software without specific prior written permission. -// -// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR -// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT -// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, -// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT -// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, -// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY -// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT -// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE -// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. -// -// Author: wan@google.com (Zhanyong Wan) -// Author: vladl@google.com (Vlad Losev) - -// This provides interface PrimeTable that determines whether a number is a -// prime and determines a next prime number. This interface is used -// in Google Test samples demonstrating use of parameterized tests. - -#ifndef GTEST_SAMPLES_PRIME_TABLES_H_ -#define GTEST_SAMPLES_PRIME_TABLES_H_ - -#include <algorithm> - -// The prime table interface. -class PrimeTable { - public: - virtual ~PrimeTable() {} - - // Returns true iff n is a prime number. - virtual bool IsPrime(int n) const = 0; - - // Returns the smallest prime number greater than p; or returns -1 - // if the next prime is beyond the capacity of the table. - virtual int GetNextPrime(int p) const = 0; -}; - -// Implementation #1 calculates the primes on-the-fly. -class OnTheFlyPrimeTable : public PrimeTable { - public: - virtual bool IsPrime(int n) const { - if (n <= 1) return false; - - for (int i = 2; i*i <= n; i++) { - // n is divisible by an integer other than 1 and itself. - if ((n % i) == 0) return false; - } - - return true; - } - - virtual int GetNextPrime(int p) const { - for (int n = p + 1; n > 0; n++) { - if (IsPrime(n)) return n; - } - - return -1; - } -}; - -// Implementation #2 pre-calculates the primes and stores the result -// in an array. -class PreCalculatedPrimeTable : public PrimeTable { - public: - // 'max' specifies the maximum number the prime table holds. - explicit PreCalculatedPrimeTable(int max) - : is_prime_size_(max + 1), is_prime_(new bool[max + 1]) { - CalculatePrimesUpTo(max); - } - virtual ~PreCalculatedPrimeTable() { delete[] is_prime_; } - - virtual bool IsPrime(int n) const { - return 0 <= n && n < is_prime_size_ && is_prime_[n]; - } - - virtual int GetNextPrime(int p) const { - for (int n = p + 1; n < is_prime_size_; n++) { - if (is_prime_[n]) return n; - } - - return -1; - } - - private: - void CalculatePrimesUpTo(int max) { - ::std::fill(is_prime_, is_prime_ + is_prime_size_, true); - is_prime_[0] = is_prime_[1] = false; - - for (int i = 2; i <= max; i++) { - if (!is_prime_[i]) continue; - - // Marks all multiples of i (except i itself) as non-prime. - for (int j = 2*i; j <= max; j += i) { - is_prime_[j] = false; - } - } - } - - const int is_prime_size_; - bool* const is_prime_; - - // Disables compiler warning "assignment operator could not be generated." - void operator=(const PreCalculatedPrimeTable& rhs); -}; - -#endif // GTEST_SAMPLES_PRIME_TABLES_H_ |