BIG_INTS_REAL

SUBMITTED BY: davindran21

DATE: Oct. 12, 2016, 1:58 a.m.

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  1. # include <cstdlib>
  2. # include <iomanip>
  3. # include <iostream>
  4. # include <ctime>
  5. # include <float.h>
  6. # include <limits.h>
  8. using namespace std;
  10. int main ( );
  11. void test01 ( );
  12. void timestamp ( );
  14. //****************************************************************************80
  16. int main ( )
  18. //****************************************************************************80
  19. //
  20. // Purpose:
  21. //
  22. // MAIN is the main program for BIG_INTS_REAL.
  23. //
  24. // Licensing:
  25. //
  26. // This code is distributed under the GNU LGPL license.
  27. //
  28. // Modified:
  29. //
  30. // 28 September 2014
  31. //
  32. // Author:
  33. //
  34. // John Burkardt
  35. //
  36. {
  37. timestamp ( );
  38. cout << "\n";
  39. cout << "BIG_INTS_REAL:\n";
  40. cout << " C++ version\n";
  41. cout << " Examine the transfer of integer values into and out of real variables.\n";
  43. test01 ( );
  44. //
  45. // Terminate.
  46. //
  47. cout << "\n";
  48. cout << "BIG_INTS_REAL:\n";
  49. cout << " Normal end of execution.\n";
  50. cout << "\n";
  51. timestamp ( );
  53. return 0;
  54. }
  55. //****************************************************************************80
  57. void test01 ( )
  59. //****************************************************************************80
  60. //
  61. // Purpose:
  62. //
  63. // TEST01 stores huge integers as reals.
  64. //
  65. // Licensing:
  66. //
  67. // This code is distributed under the GNU LGPL license.
  68. //
  69. // Modified:
  70. //
  71. // 28 September 2014
  72. //
  73. // Author:
  74. //
  75. // John Burkardt
  76. //
  77. {
  78. int i4;
  79. int i4r4i4;
  80. int i4r8i4;
  81. long long int i8;
  82. long long int i8r4i8;
  83. long long int i8r8i8;
  84. float r4;
  85. float r4i4;
  86. float r4i8;
  87. double r8;
  88. double r8i4;
  89. double r8i8;
  91. cout << "\n";
  92. cout << "TEST01\n";
  93. cout << " Compute the largest possible integers.\n";
  94. cout << " Try to store them as real values.\n";
  95. cout << " Then copy them back.\n";
  97. cout << "\n";
  98. cout << " 'Huge' integers and huge reals:\n";
  99. cout << "\n";
  101. i4 = INT_MAX;
  102. i8 = LLONG_MAX;
  103. r4 = FLT_MAX;
  104. r8 = DBL_MAX;
  106. cout << " i4 = INT_MAX = " << i4 << "\n";
  107. cout << " i8 = LLONG_MAX = " << i8 << "\n";
  108. cout << " r4 = FLT_MAX = " << r4 << "\n";
  109. cout << " r8 = DBL_MAX = " << r8 << "\n";
  111. cout << "\n";
  112. cout << " Convert huge integers to real values:\n";
  113. cout << "\n";
  115. r4i4 = ( float ) ( i4 );
  116. r4i8 = ( float ) ( i8 );
  117. r8i4 = ( double ) ( i4 );
  118. r8i8 = ( double ) ( i8 );
  120. cout << " r4i4 = ( float ) ( i4 ) = " << r4i4 << "\n";
  121. cout << " r4i8 = ( float ) ( i8 ) = " << r4i8 << "\n";
  122. cout << " r8i4 = ( double ) ( i4 ) = " << r8i4 << "\n";
  123. cout << " r8i8 = ( double ) ( i8 ) = " << r8i8 << "\n";
  125. cout << "\n";
  126. cout << " Convert real values of integers back to integers:\n";
  127. cout << "\n";
  129. i4r4i4 = ( int ) ( r4i4 );
  130. i4r8i4 = ( int ) ( r8i4 );
  131. i8r4i8 = ( long long int ) ( r4i8 );
  132. i8r8i8 = ( long long int ) ( r8i8 );
  134. cout << " i4r4i4 = ( int ) ( r4i4 ) = " << i4r4i4 << "\n";
  135. cout << " i4r8i4 = ( int ) ( r8i4 ) = " << i4r8i4 << "\n";
  136. cout << " i8r4i8 = ( long long int ) ( r4i8 ) = " << i8r4i8 << "\n";
  137. cout << " i8r8i8 = ( long long int ) ( r8i8 ) = " << i8r8i8 << "\n";
  139. return;
  140. }
  141. //****************************************************************************80
  143. void timestamp ( )
  145. //****************************************************************************80
  146. //
  147. // Purpose:
  148. //
  149. // TIMESTAMP prints the current YMDHMS date as a time stamp.
  150. //
  151. // Example:
  152. //
  153. // 31 May 2001 09:45:54 AM
  154. //
  155. // Licensing:
  156. //
  157. // This code is distributed under the GNU LGPL license.
  158. //
  159. // Modified:
  160. //
  161. // 08 July 2009
  162. //
  163. // Author:
  164. //
  165. // John Burkardt
  166. //
  167. // Parameters:
  168. //
  169. // None
  170. //
  171. {
  172. # define TIME_SIZE 40
  174. static char time_buffer[TIME_SIZE];
  175. const struct std::tm *tm_ptr;
  176. size_t len;
  177. std::time_t now;
  179. now = std::time ( NULL );
  180. tm_ptr = std::localtime ( &now );
  182. len = std::strftime ( time_buffer, TIME_SIZE, "%d %B %Y %I:%M:%S %p", tm_ptr );
  184. std::cout << time_buffer << "\n";
  186. return;
  187. # undef TIME_SIZE
  188. }
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