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  1. #include <chrono>
  2. #include <iostream>
  3. #include <cmath>
  4.  
  5. class TimeMeasure {
  6. public:
  7.    TimeMeasure() {
  8.       start();
  9.    }
  10.    void start() {
  11.       m_start = now();
  12.    }
  13.    int elapsed_ms() const {
  14.       return elapsed< std::chrono::milliseconds >();
  15.    }
  16.    int elapsed_mks() const {
  17.       return elapsed< std::chrono::microseconds >();
  18.    }
  19.  
  20. private:
  21.    template< class D >
  22.    int elapsed() const {
  23.       return std::chrono::duration_cast< D >( now() - m_start ).count();
  24.    }
  25.    const std::chrono::system_clock::time_point now() const {
  26.       return std::chrono::system_clock::now();
  27.    }
  28.    std::chrono::system_clock::time_point m_start;
  29. };
  30.  
  31. template< class F >
  32. void measure_ms( const char * const text, F f ) {
  33.    TimeMeasure m;
  34.    f();
  35.    int t = m.elapsed_ms();
  36.    std::cout << text << " : " << t << " ms." << std::endl;
  37. }
  38.  
  39. template< class F >
  40. void measure_mks( const char * const text, F f ) {
  41.    TimeMeasure m;
  42.    f();
  43.    int t = m.elapsed_mks();
  44.    std::cout << text << " : " << t << " mks." << std::endl;
  45. }
  46.  
  47. const int times = 1000000;
  48.  
  49. double MODF()
  50. {
  51.  	double param, fractpart, intpart;	
  52. 	for( int i=0; i<times; ++i )
  53. 	{
  54. 	  	param = rand();
  55. 		fractpart = modf (param , &intpart);
  56. 	}
  57. 	return intpart;
  58. }
  59.  
  60. double MODF_CASTAWAY()
  61. {
  62. 	double param;
  63. 	int fractpart, intpart;	
  64. 	for( int i=0; i<times; ++i )
  65. 	{
  66. 	  	param = rand();
  67. 		intpart = (int)floor( param );
  68. 		fractpart = (int)((param - intpart));
  69. 	}
  70. 	return intpart;	
  71. }
  72.  
  73. int main()
  74. {
  75. 	measure_mks( "modf_castaway", MODF_CASTAWAY );
  76. 	measure_mks( "modf", MODF );	
  77. }
  78.  
Success #stdin #stdout 0.11s 3296KB
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Standard input is empty
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modf_castaway : 63857 mks.
modf : 44849 mks.
https://ideone.com/rRG6Hq
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
secret

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