# include # include # include # include # include # include using namespace std; int main ( ); void test01 ( ); void timestamp ( ); //****************************************************************************80 int main ( ) //****************************************************************************80 // // Purpose: // // MAIN is the main program for BIG_INTS_REAL. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 28 September 2014 // // Author: // // John Burkardt // { timestamp ( ); cout << "\n"; cout << "BIG_INTS_REAL:\n"; cout << " C++ version\n"; cout << " Examine the transfer of integer values into and out of real variables.\n"; test01 ( ); // // Terminate. // cout << "\n"; cout << "BIG_INTS_REAL:\n"; cout << " Normal end of execution.\n"; cout << "\n"; timestamp ( ); return 0; } //****************************************************************************80 void test01 ( ) //****************************************************************************80 // // Purpose: // // TEST01 stores huge integers as reals. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 28 September 2014 // // Author: // // John Burkardt // { int i4; int i4r4i4; int i4r8i4; long long int i8; long long int i8r4i8; long long int i8r8i8; float r4; float r4i4; float r4i8; double r8; double r8i4; double r8i8; cout << "\n"; cout << "TEST01\n"; cout << " Compute the largest possible integers.\n"; cout << " Try to store them as real values.\n"; cout << " Then copy them back.\n"; cout << "\n"; cout << " 'Huge' integers and huge reals:\n"; cout << "\n"; i4 = INT_MAX; i8 = LLONG_MAX; r4 = FLT_MAX; r8 = DBL_MAX; cout << " i4 = INT_MAX = " << i4 << "\n"; cout << " i8 = LLONG_MAX = " << i8 << "\n"; cout << " r4 = FLT_MAX = " << r4 << "\n"; cout << " r8 = DBL_MAX = " << r8 << "\n"; cout << "\n"; cout << " Convert huge integers to real values:\n"; cout << "\n"; r4i4 = ( float ) ( i4 ); r4i8 = ( float ) ( i8 ); r8i4 = ( double ) ( i4 ); r8i8 = ( double ) ( i8 ); cout << " r4i4 = ( float ) ( i4 ) = " << r4i4 << "\n"; cout << " r4i8 = ( float ) ( i8 ) = " << r4i8 << "\n"; cout << " r8i4 = ( double ) ( i4 ) = " << r8i4 << "\n"; cout << " r8i8 = ( double ) ( i8 ) = " << r8i8 << "\n"; cout << "\n"; cout << " Convert real values of integers back to integers:\n"; cout << "\n"; i4r4i4 = ( int ) ( r4i4 ); i4r8i4 = ( int ) ( r8i4 ); i8r4i8 = ( long long int ) ( r4i8 ); i8r8i8 = ( long long int ) ( r8i8 ); cout << " i4r4i4 = ( int ) ( r4i4 ) = " << i4r4i4 << "\n"; cout << " i4r8i4 = ( int ) ( r8i4 ) = " << i4r8i4 << "\n"; cout << " i8r4i8 = ( long long int ) ( r4i8 ) = " << i8r4i8 << "\n"; cout << " i8r8i8 = ( long long int ) ( r8i8 ) = " << i8r8i8 << "\n"; return; } //****************************************************************************80 void timestamp ( ) //****************************************************************************80 // // Purpose: // // TIMESTAMP prints the current YMDHMS date as a time stamp. // // Example: // // 31 May 2001 09:45:54 AM // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 08 July 2009 // // Author: // // John Burkardt // // Parameters: // // None // { # define TIME_SIZE 40 static char time_buffer[TIME_SIZE]; const struct std::tm *tm_ptr; size_t len; std::time_t now; now = std::time ( NULL ); tm_ptr = std::localtime ( &now ); len = std::strftime ( time_buffer, TIME_SIZE, "%d %B %Y %I:%M:%S %p", tm_ptr ); std::cout << time_buffer << "\n"; return; # undef TIME_SIZE }