90 lines
1.4 KiB
C++
90 lines
1.4 KiB
C++
/*
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VIM: let b:lcppflags="-std=c++14 -O2 -pthread -I."
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VIM: let b:wcppflags="/O2 /EHsc /DWIN32"
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VIM-: let b:cppflags=g:Iboost.g:Itbb
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VIM-: let b:ldflags=g:Lboost.g:Ltbb
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VIM-: let b:ldlibpath=g:Bboost.g:Btbb
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VIM-: let b:argv=""
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*/
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#include <iostream>
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#include <exception>
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#include <chrono>
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template <int N>
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struct power_of
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{
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enum {
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value = power_of<(N+1)/2>::value * 2
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};
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};
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template <>
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struct power_of<2>
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{
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enum {
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value = 2
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};
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};
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template <>
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struct power_of<1>
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{
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enum {
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value = 1
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};
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};
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template <>
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struct power_of<0>
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{
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enum {
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value = 0
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};
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};
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template <int N>
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void test()
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{
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std::cout << N << "=> " << power_of<N>::value <<std::endl;
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}
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int main ( void )
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{try{
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auto begin = std::chrono::high_resolution_clock::now();
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test<0>();
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test<1>();
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test<2>();
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test<3>();
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test<4>();
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test<5>();
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test<6>();
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test<7>();
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test<8>();
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test<9>();
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test<127>();
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test<128>();
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test<129>();
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//......
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auto end = std::chrono::high_resolution_clock::now();
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std::chrono::duration<double> seconds = end - begin;
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std::cout << "Time: " << seconds.count() << std::endl;
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return 0;
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}
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catch ( const std::exception& e )
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{
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std::cerr << std::endl
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<< "std::exception(\"" << e.what() << "\")." << std::endl;
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return 2;
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}
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catch ( ... )
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{
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std::cerr << std::endl
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<< "unknown exception." << std::endl;
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return 1;
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}}
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