# include # include # include # include # include # include # include using namespace std; int main ( ); char ch_cap ( char ch ); bool ch_eqi ( char ch1, char ch2 ); int ch_to_digit ( char ch ); int file_column_count ( string input_filename ); int file_row_count ( string input_filename ); void perm_next3 ( int n, int p[], bool &more ); double r8_huge ( ); double *r8mat_data_read ( string input_filename, int m, int n ); void r8mat_header_read ( string input_filename, int &m, int &n ); void r8mat_print ( int m, int n, double a[], string title ); void r8mat_print_some ( int m, int n, double a[], int ilo, int jlo, int ihi, int jhi, string title ); int s_len_trim ( string s ); double s_to_r8 ( string s, int *lchar, bool *error ); bool s_to_r8vec ( string s, int n, double rvec[] ); int s_word_count ( string s ); void timestamp ( ); //****************************************************************************80 int main ( ) //****************************************************************************80 // // Purpose: // // MAIN is the main program for TSP_BRUTE. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 04 December 2013 // // Author: // // John Burkardt // { double *distance; string distance_filename; int i; int i1; int i2; int m; bool more; int n; int *p; int *p_min; int paths; double total; double total_ave; double total_max; double total_min; timestamp ( ); cout << "\n"; cout << "TSP_BRUTE:\n"; cout << " C++ version\n"; cout << " Solve small traveling salesman problems by brute force.\n"; // // Get the distance table. // cout << "\n"; cout << " Enter the name of the file containing\n"; cout << " the city-to-city distance table.\n"; cin >> distance_filename; r8mat_header_read ( distance_filename, m, n ); cout << "\n"; cout << " Number of cities is " << n << "\n"; distance = r8mat_data_read ( distance_filename, n, n ); // // Print the distance matrix. // r8mat_print ( n, n, distance, " Distance matrix:" ); // // Examine every permutation. // total_max = - r8_huge ( ); total_min = r8_huge ( ); total_ave = 0.0; more = false; p = new int[n]; p_min = new int[n]; paths = 0; for ( ; ; ) { perm_next3 ( n, p, more ); paths = paths + 1; total = 0.0; i1 = n - 1; for ( i2 = 0; i2 < n; i2++ ) { total = total + distance[p[i1]+p[i2]*n]; i1 = i2; } total_ave = total_ave + total; if ( total_max < total ) { total_max = total; } if ( total < total_min ) { total_min = total; for ( i = 0; i < n; i++ ) { p_min[i] = p[i]; } } if ( ! more ) { break; } } total_ave = total_ave / ( double ) ( paths ); cout << "\n"; cout << " Itinerary:\n"; cout << " Step From To Distance\n"; cout << "\n"; i1 = n - 1; for ( i2 = 0; i2 < n; i2++ ) { cout << " " << setw(4) << i2 << " " << setw(2) << p_min[i1] << " " << setw(2) << p_min[i2] << " " << distance[p_min[i1]+p_min[i2]*n] << "\n"; i1 = i2; } cout << "\n"; cout << " Total: " << total_min << "\n"; cout << "\n"; cout << " Number of paths checked = " << paths << "\n"; cout << "\n"; cout << " Minimum length = " << total_min << "\n"; cout << " Average length = " << total_ave << "\n"; cout << " Maximum length = " << total_max << "\n"; // // Free memory. // delete [] distance; delete [] p; delete [] p_min; /* Terminate. */ cout << "\n"; cout << "TSP_BRUTE\n"; cout << " Normal end of execution.\n"; cout << "\n"; timestamp ( ); return 0; } //****************************************************************************80 char ch_cap ( char ch ) //****************************************************************************80 // // Purpose: // // CH_CAP capitalizes a single character. // // Discussion: // // This routine should be equivalent to the library "toupper" function. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 19 July 1998 // // Author: // // John Burkardt // // Parameters: // // Input, char CH, the character to capitalize. // // Output, char CH_CAP, the capitalized character. // { if ( 97 <= ch && ch <= 122 ) { ch = ch - 32; } return ch; } //****************************************************************************80 bool ch_eqi ( char ch1, char ch2 ) //****************************************************************************80 // // Purpose: // // CH_EQI is true if two characters are equal, disregarding case. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 13 June 2003 // // Author: // // John Burkardt // // Parameters: // // Input, char CH1, CH2, the characters to compare. // // Output, bool CH_EQI, is true if the two characters are equal, // disregarding case. // { if ( 97 <= ch1 && ch1 <= 122 ) { ch1 = ch1 - 32; } if ( 97 <= ch2 && ch2 <= 122 ) { ch2 = ch2 - 32; } return ( ch1 == ch2 ); } //****************************************************************************80 int ch_to_digit ( char ch ) //****************************************************************************80 // // Purpose: // // CH_TO_DIGIT returns the integer value of a base 10 digit. // // Example: // // CH DIGIT // --- ----- // '0' 0 // '1' 1 // ... ... // '9' 9 // ' ' 0 // 'X' -1 // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 13 June 2003 // // Author: // // John Burkardt // // Parameters: // // Input, char CH, the decimal digit, '0' through '9' or blank are legal. // // Output, int CH_TO_DIGIT, the corresponding integer value. If the // character was 'illegal', then DIGIT is -1. // { int digit; if ( '0' <= ch && ch <= '9' ) { digit = ch - '0'; } else if ( ch == ' ' ) { digit = 0; } else { digit = -1; } return digit; } //****************************************************************************80 int file_column_count ( string filename ) //****************************************************************************80 // // Purpose: // // FILE_COLUMN_COUNT counts the columns in the first line of a file. // // Discussion: // // The file is assumed to be a simple text file. // // Most lines of the file are presumed to consist of COLUMN_NUM words, // separated by spaces. There may also be some blank lines, and some // comment lines, which have a "#" in column 1. // // The routine tries to find the first non-comment non-blank line and // counts the number of words in that line. // // If all lines are blanks or comments, it goes back and tries to analyze // a comment line. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 05 July 2009 // // Author: // // John Burkardt // // Parameters: // // Input, string FILENAME, the name of the file. // // Output, int FILE_COLUMN_COUNT, the number of columns assumed // to be in the file. // { int column_num; ifstream input; bool got_one; string text; // // Open the file. // input.open ( filename.c_str ( ) ); if ( !input ) { column_num = -1; cerr << "\n"; cerr << "FILE_COLUMN_COUNT - Fatal error!\n"; cerr << " Could not open the file:\n"; cerr << " \"" << filename << "\"\n"; exit ( 1 ); } // // Read one line, but skip blank lines and comment lines. // got_one = false; for ( ; ; ) { getline ( input, text ); if ( input.eof ( ) ) { break; } if ( s_len_trim ( text ) <= 0 ) { continue; } if ( text[0] == '#' ) { continue; } got_one = true; break; } if ( !got_one ) { input.close ( ); input.open ( filename.c_str ( ) ); for ( ; ; ) { input >> text; if ( input.eof ( ) ) { break; } if ( s_len_trim ( text ) == 0 ) { continue; } got_one = true; break; } } input.close ( ); if ( !got_one ) { cerr << "\n"; cerr << "FILE_COLUMN_COUNT - Warning!\n"; cerr << " The file does not seem to contain any data.\n"; return -1; } column_num = s_word_count ( text ); return column_num; } //****************************************************************************80 int file_row_count ( string input_filename ) //****************************************************************************80 // // Purpose: // // FILE_ROW_COUNT counts the number of row records in a file. // // Discussion: // // It does not count lines that are blank, or that begin with a // comment symbol '#'. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 February 2009 // // Author: // // John Burkardt // // Parameters: // // Input, string INPUT_FILENAME, the name of the input file. // // Output, int FILE_ROW_COUNT, the number of rows found. // { int bad_num; int comment_num; ifstream input; int i; string line; int record_num; int row_num; row_num = 0; comment_num = 0; record_num = 0; bad_num = 0; input.open ( input_filename.c_str ( ) ); if ( !input ) { cerr << "\n"; cerr << "FILE_ROW_COUNT - Fatal error!\n"; cerr << " Could not open the input file: \"" << input_filename << "\"\n"; exit ( 1 ); } for ( ; ; ) { getline ( input, line ); if ( input.eof ( ) ) { break; } record_num = record_num + 1; if ( line[0] == '#' ) { comment_num = comment_num + 1; continue; } if ( s_len_trim ( line ) == 0 ) { comment_num = comment_num + 1; continue; } row_num = row_num + 1; } input.close ( ); return row_num; } //****************************************************************************80 void perm_next3 ( int n, int p[], bool &more ) //****************************************************************************80 // // Purpose: // // PERM_NEXT3 computes all of the permutations of N objects, one at a time. // // Discussion: // // The routine is initialized by calling with MORE = TRUE in which case // it returns the identity permutation. // // If the routine is called with MORE = FALSE then the successor of the // input permutation is computed. // // Trotter's algorithm is used. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 06 July 2003 // // Author: // // Original FORTRAN77 version by H Trotter, // C++ version by John Burkardt. // // Reference: // // H Trotter, // PERM, Algorithm 115, // Communications of the Association for Computing Machinery, // Volume 5, 1962, pages 434-435. // // Parameters: // // Input, int N, the number of objects being permuted. // // Input/output, int P[N], the permutation, in standard index form. // If MORE is TRUE, then P is assumed to contain the // "previous" permutation, and on P(I) is the value // of the I-th object under the next permutation. // Otherwise, P will be set to the "first" permutation. // // Input/output, bool &MORE. // Set MORE = FALSE before first calling this routine. // MORE will be reset to TRUE and a permutation will be returned. // Each new call produces a new permutation until MORE is returned FALSE // { int i; int m2; int n2; static int nfact = 0; int q; static int rank = 0; int s; int t; int temp; if ( !more ) { for ( i = 0; i < n; i++ ) { p[i] = i; } more = true; rank = 1; nfact = 1; for ( i = 1; i <= n; i++ ) { nfact = nfact * i; } } else { n2 = n; m2 = rank; s = n; for ( ; ; ) { q = m2 % n2; t = m2 % ( 2 * n2 ); if ( q != 0 ) { break; } if ( t == 0 ) { s = s - 1; } m2 = m2 / n2; n2 = n2 - 1; } if ( q == t ) { s = s - q; } else { s = s + q - n2; } temp = p[s-1]; p[s-1] = p[s]; p[s] = temp; rank = rank + 1; if ( rank == nfact ) { more = false; } } return; } //****************************************************************************80 double r8_huge ( ) //****************************************************************************80 // // Purpose: // // R8_HUGE returns a "huge" R8. // // Discussion: // // The value returned by this function is NOT required to be the // maximum representable R8. This value varies from machine to machine, // from compiler to compiler, and may cause problems when being printed. // We simply want a "very large" but non-infinite number. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 06 October 2007 // // Author: // // John Burkardt // // Parameters: // // Output, double R8_HUGE, a "huge" R8 value. // { double value; value = 1.0E+30; return value; } //****************************************************************************80 double *r8mat_data_read ( string input_filename, int m, int n ) //****************************************************************************80 // // Purpose: // // R8MAT_DATA_READ reads the data from an R8MAT file. // // Discussion: // // An R8MAT is an array of R8's. // // The file is assumed to contain one record per line. // // Records beginning with '#' are comments, and are ignored. // Blank lines are also ignored. // // Each line that is not ignored is assumed to contain exactly (or at least) // M real numbers, representing the coordinates of a point. // // There are assumed to be exactly (or at least) N such records. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 February 2009 // // Author: // // John Burkardt // // Parameters: // // Input, string INPUT_FILENAME, the name of the input file. // // Input, int M, the number of spatial dimensions. // // Input, int N, the number of points. The program // will stop reading data once N values have been read. // // Output, double R8MAT_DATA_READ[M*N], the data. // { bool error; ifstream input; int i; int j; string line; double *table; double *x; input.open ( input_filename.c_str ( ) ); if ( !input ) { cerr << "\n"; cerr << "R8MAT_DATA_READ - Fatal error!\n"; cerr << " Could not open the input file: \"" << input_filename << "\"\n"; exit ( 1 ); } table = new double[m*n]; x = new double[m]; j = 0; while ( j < n ) { getline ( input, line ); if ( input.eof ( ) ) { break; } if ( line[0] == '#' || s_len_trim ( line ) == 0 ) { continue; } error = s_to_r8vec ( line, m, x ); if ( error ) { continue; } for ( i = 0; i < m; i++ ) { table[i+j*m] = x[i]; } j = j + 1; } input.close ( ); delete [] x; return table; } //****************************************************************************80 void r8mat_header_read ( string input_filename, int &m, int &n ) //****************************************************************************80 // // Purpose: // // R8MAT_HEADER_READ reads the header from an R8MAT file. // // Discussion: // // An R8MAT is an array of R8's. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 04 December 2013 // // Author: // // John Burkardt // // Parameters: // // Input, string INPUT_FILENAME, the name of the input file. // // Output, int &M, the number of spatial dimensions. // // Output, int &N, the number of points. // { m = file_column_count ( input_filename ); if ( m <= 0 ) { cerr << "\n"; cerr << "R8MAT_HEADER_READ - Fatal error!\n"; cerr << " FILE_COLUMN_COUNT failed.\n"; exit ( 1 ); } n = file_row_count ( input_filename ); if ( n <= 0 ) { cerr << "\n"; cerr << "R8MAT_HEADER_READ - Fatal error!\n"; cerr << " FILE_ROW_COUNT failed.\n"; exit ( 1 ); } return; } //****************************************************************************80 void r8mat_print ( int m, int n, double a[], string title ) //****************************************************************************80 // // Purpose: // // R8MAT_PRINT prints an R8MAT, with an optional title. // // Discussion: // // An R8MAT is an array of R8's. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 29 August 2003 // // Author: // // John Burkardt // // Parameters: // // Input, int M, the number of rows in A. // // Input, int N, the number of columns in A. // // Input, double A[M*N], the M by N matrix. // // Input, string TITLE, a title. // { r8mat_print_some ( m, n, a, 1, 1, m, n, title ); return; } //****************************************************************************80 void r8mat_print_some ( int m, int n, double a[], int ilo, int jlo, int ihi, int jhi, string title ) //****************************************************************************80 // // Purpose: // // R8MAT_PRINT_SOME prints some of an R8MAT. // // Discussion: // // An R8MAT is a doubly dimensioned array of R8 values, stored as a vector // in column-major order. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 26 June 2013 // // Author: // // John Burkardt // // Parameters: // // Input, int M, the number of rows of the matrix. // M must be positive. // // Input, int N, the number of columns of the matrix. // N must be positive. // // Input, double A[M*N], the matrix. // // Input, int ILO, JLO, IHI, JHI, designate the first row and // column, and the last row and column to be printed. // // Input, string TITLE, a title. // { # define INCX 5 int i; int i2hi; int i2lo; int j; int j2hi; int j2lo; cout << "\n"; cout << title << "\n"; if ( m <= 0 || n <= 0 ) { cout << "\n"; cout << " (None)\n"; return; } // // Print the columns of the matrix, in strips of 5. // for ( j2lo = jlo; j2lo <= jhi; j2lo = j2lo + INCX ) { j2hi = j2lo + INCX - 1; if ( n < j2hi ) { j2hi = n; } if ( jhi < j2hi ) { j2hi = jhi; } cout << "\n"; // // For each column J in the current range... // // Write the header. // cout << " Col: "; for ( j = j2lo; j <= j2hi; j++ ) { cout << setw(7) << j - 1 << " "; } cout << "\n"; cout << " Row\n"; cout << "\n"; // // Determine the range of the rows in this strip. // if ( 1 < ilo ) { i2lo = ilo; } else { i2lo = 1; } if ( ihi < m ) { i2hi = ihi; } else { i2hi = m; } for ( i = i2lo; i <= i2hi; i++ ) { // // Print out (up to) 5 entries in row I, that lie in the current strip. // cout << setw(5) << i - 1 << ": "; for ( j = j2lo; j <= j2hi; j++ ) { cout << setw(12) << a[i-1+(j-1)*m] << " "; } cout << "\n"; } } return; # undef INCX } //****************************************************************************80 int s_len_trim ( string s ) //****************************************************************************80 // // Purpose: // // S_LEN_TRIM returns the length of a string to the last nonblank. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 05 July 2009 // // Author: // // John Burkardt // // Parameters: // // Input, string S, a string. // // Output, int S_LEN_TRIM, the length of the string to the last nonblank. // If S_LEN_TRIM is 0, then the string is entirely blank. // { int n; n = s.length ( ); while ( 0 < n ) { if ( s[n-1] != ' ' ) { return n; } n = n - 1; } return n; } //****************************************************************************80 double s_to_r8 ( string s, int *lchar, bool *error ) //****************************************************************************80 // // Purpose: // // S_TO_R8 reads an R8 from a string. // // Discussion: // // This routine will read as many characters as possible until it reaches // the end of the string, or encounters a character which cannot be // part of the real number. // // Legal input is: // // 1 blanks, // 2 '+' or '-' sign, // 2.5 spaces // 3 integer part, // 4 decimal point, // 5 fraction part, // 6 'E' or 'e' or 'D' or 'd', exponent marker, // 7 exponent sign, // 8 exponent integer part, // 9 exponent decimal point, // 10 exponent fraction part, // 11 blanks, // 12 final comma or semicolon. // // with most quantities optional. // // Example: // // S R // // '1' 1.0 // ' 1 ' 1.0 // '1A' 1.0 // '12,34,56' 12.0 // ' 34 7' 34.0 // '-1E2ABCD' -100.0 // '-1X2ABCD' -1.0 // ' 2E-1' 0.2 // '23.45' 23.45 // '-4.2E+2' -420.0 // '17d2' 1700.0 // '-14e-2' -0.14 // 'e2' 100.0 // '-12.73e-9.23' -12.73 * 10.0^(-9.23) // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 05 July 2009 // // Author: // // John Burkardt // // Parameters: // // Input, string S, the string containing the // data to be read. Reading will begin at position 1 and // terminate at the end of the string, or when no more // characters can be read to form a legal real. Blanks, // commas, or other nonnumeric data will, in particular, // cause the conversion to halt. // // Output, int *LCHAR, the number of characters read from // the string to form the number, including any terminating // characters such as a trailing comma or blanks. // // Output, bool *ERROR, is true if an error occurred. // // Output, double S_TO_R8, the real value that was read from the string. // { char c; int ihave; int isgn; int iterm; int jbot; int jsgn; int jtop; int nchar; int ndig; double r; double rbot; double rexp; double rtop; char TAB = 9; nchar = s_len_trim ( s ); *error = false; r = 0.0; *lchar = -1; isgn = 1; rtop = 0.0; rbot = 1.0; jsgn = 1; jtop = 0; jbot = 1; ihave = 1; iterm = 0; for ( ; ; ) { c = s[*lchar+1]; *lchar = *lchar + 1; // // Blank or TAB character. // if ( c == ' ' || c == TAB ) { if ( ihave == 2 ) { } else if ( ihave == 6 || ihave == 7 ) { iterm = 1; } else if ( 1 < ihave ) { ihave = 11; } } // // Comma. // else if ( c == ',' || c == ';' ) { if ( ihave != 1 ) { iterm = 1; ihave = 12; *lchar = *lchar + 1; } } // // Minus sign. // else if ( c == '-' ) { if ( ihave == 1 ) { ihave = 2; isgn = -1; } else if ( ihave == 6 ) { ihave = 7; jsgn = -1; } else { iterm = 1; } } // // Plus sign. // else if ( c == '+' ) { if ( ihave == 1 ) { ihave = 2; } else if ( ihave == 6 ) { ihave = 7; } else { iterm = 1; } } // // Decimal point. // else if ( c == '.' ) { if ( ihave < 4 ) { ihave = 4; } else if ( 6 <= ihave && ihave <= 8 ) { ihave = 9; } else { iterm = 1; } } // // Exponent marker. // else if ( ch_eqi ( c, 'E' ) || ch_eqi ( c, 'D' ) ) { if ( ihave < 6 ) { ihave = 6; } else { iterm = 1; } } // // Digit. // else if ( ihave < 11 && '0' <= c && c <= '9' ) { if ( ihave <= 2 ) { ihave = 3; } else if ( ihave == 4 ) { ihave = 5; } else if ( ihave == 6 || ihave == 7 ) { ihave = 8; } else if ( ihave == 9 ) { ihave = 10; } ndig = ch_to_digit ( c ); if ( ihave == 3 ) { rtop = 10.0 * rtop + ( double ) ndig; } else if ( ihave == 5 ) { rtop = 10.0 * rtop + ( double ) ndig; rbot = 10.0 * rbot; } else if ( ihave == 8 ) { jtop = 10 * jtop + ndig; } else if ( ihave == 10 ) { jtop = 10 * jtop + ndig; jbot = 10 * jbot; } } // // Anything else is regarded as a terminator. // else { iterm = 1; } // // If we haven't seen a terminator, and we haven't examined the // entire string, go get the next character. // if ( iterm == 1 || nchar <= *lchar + 1 ) { break; } } // // If we haven't seen a terminator, and we have examined the // entire string, then we're done, and LCHAR is equal to NCHAR. // if ( iterm != 1 && (*lchar) + 1 == nchar ) { *lchar = nchar; } // // Number seems to have terminated. Have we got a legal number? // Not if we terminated in states 1, 2, 6 or 7! // if ( ihave == 1 || ihave == 2 || ihave == 6 || ihave == 7 ) { *error = true; return r; } // // Number seems OK. Form it. // if ( jtop == 0 ) { rexp = 1.0; } else { if ( jbot == 1 ) { rexp = pow ( 10.0, jsgn * jtop ); } else { rexp = jsgn * jtop; rexp = rexp / jbot; rexp = pow ( 10.0, rexp ); } } r = isgn * rexp * rtop / rbot; return r; } //****************************************************************************80 bool s_to_r8vec ( string s, int n, double rvec[] ) //****************************************************************************80 // // Purpose: // // S_TO_R8VEC reads an R8VEC from a string. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 05 July 2009 // // Author: // // John Burkardt // // Parameters: // // Input, string S, the string to be read. // // Input, int N, the number of values expected. // // Output, double RVEC[N], the values read from the string. // // Output, bool S_TO_R8VEC, is true if an error occurred. // { int begin; bool error; int i; int lchar; int length; begin = 0; length = s.length ( ); error = 0; for ( i = 0; i < n; i++ ) { rvec[i] = s_to_r8 ( s.substr(begin,length), &lchar, &error ); if ( error ) { return error; } begin = begin + lchar; length = length - lchar; } return error; } //****************************************************************************80 int s_word_count ( string s ) //****************************************************************************80 // // Purpose: // // S_WORD_COUNT counts the number of "words" in a string. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 05 July 2009 // // Author: // // John Burkardt // // Parameters: // // Input, string S, the string to be examined. // // Output, int S_WORD_COUNT, the number of "words" in the string. // Words are presumed to be separated by one or more blanks. // { bool blank; int char_count; int i; int word_count; word_count = 0; blank = true; char_count = s.length ( ); for ( i = 0; i < char_count; i++ ) { if ( isspace ( s[i] ) ) { blank = true; } else if ( blank ) { word_count = word_count + 1; blank = false; } } return word_count; } //****************************************************************************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 GNU LGPL 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 }