/*============================================================================== | | File Name: | | ppIO.c | | Description: | | Command line parsing and polynomial pretty printing. | | Functions: | | parse_command_line | write_poly | | LEGAL | | Primpoly Version 13.0 - A Program for Computing Primitive Polynomials. | Copyright (C) 1999-2017 by Sean Erik O'Connor. All Rights Reserved. | | This program is free software: you can redistribute it and/or modify | it under the terms of the GNU General Public License as published by | the Free Software Foundation, either version 3 of the License, or | (at your option) any later version. | | This program is distributed in the hope that it will be useful, | but WITHOUT ANY WARRANTY; without even the implied warranty of | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | GNU General Public License for more details. | | You should have received a copy of the GNU General Public License | along with this program. If not, see <http://www.gnu.org/licenses/>. | | The author's address is artificer!AT!seanerikoconnor!DOT!freeservers!DOT!com | with !DOT! replaced by . and the !AT! replaced by @ | ==============================================================================*/ /*------------------------------------------------------------------------------ | Include Files | ------------------------------------------------------------------------------*/ #include <stdio.h> /* for printf() */ #include <stdlib.h> /* for _MAX_PATH */ #include "Primpoly.h" /*============================================================================== | parse_command_line | ================================================================================ DESCRIPTION Parse the command line. INPUT n a[] (int *) Coefficients of the nth degree polynomial a(x) = a x + ... n + a x + a. a is stored at array location a[i], 1 0 i 0 <= i < n . n (int) The polynomial's degree. OUTPUT testPolynomialForPrimitivity EXAMPLE CALLING SEQUENCE pp -h Prints help. pp -s 2 4 Prints search statistics. pp -t 2 4 x^3+x^2+1 Checks a polynomial for primitivity. No blanks, please! pp -a 2 4 Lists all primitive polynomials of degree 4 modulo 2. pp -c 2 4 Does a time-consuming double check on primitivity. METHOD BUGS None. -------------------------------------------------------------------------------- | Function Call | ------------------------------------------------------------------------------*/ int parse_command_line( int argc, char * argv[], int * testPolynomialForPrimitivity, int * listAllPrimitivePolynomials, int * printStatistics, int * printHelp, int * selfCheck, int * p, int * n, int * testPolynomial ) { int input_arg_index ; char * input_arg_string ; char * option_ptr ; int num_arg ; char * arg_string[ _MAX_PATH ] ; /* Initialize to defaults. */ *testPolynomialForPrimitivity = NO ; *listAllPrimitivePolynomials = NO ; *printStatistics = NO ; *printHelp = NO ; *selfCheck = NO ; *p = 0 ; *n = 0 ; testPolynomial = (int *) 0 ; /* * Parse the command line to get the options and their inputs. */ for (input_arg_index = 0, num_arg = 0 ; input_arg_index < argc ; ++input_arg_index) { /* Get next argument string. */ input_arg_string = argv[ input_arg_index ] ; /* We have an option: a hyphen followed by a non-null string. */ if (input_arg_string[ 0 ] == '-' && input_arg_string[ 1 ] != '\0') { /* Scan all options. */ for (option_ptr = input_arg_string + 1 ; *option_ptr != '\0' ; ++option_ptr) { switch( *option_ptr ) { /* Test a given polynomial for primitivity. */ case 't': *testPolynomialForPrimitivity = YES ; break ; /* List all primitive polynomials. */ case 'a': *listAllPrimitivePolynomials = YES ; break ; /* Print statistics on program operation. */ case 's': *printStatistics = YES ; break ; /* Print help. */ case 'h': case 'H': *printHelp = YES ; break ; /* Turn on all self-checking (slow!). */ case 'c': *selfCheck = YES ; break ; default: printf( "Cannot recognize the option %c\n", *option_ptr ) ; break ; } } } else /* Not an option, but an argument. */ { arg_string[ num_arg++ ] = input_arg_string ; } } /* Assume the next two arguments are p and n. */ if (num_arg == 3) { *p = atoi( arg_string[ 1 ] ) ; *n = atoi( arg_string[ 2 ] ) ; } else { printf( "ERROR: Expecting two arguments, p and n.\n\n" ) ; *printHelp = YES ; } return 0 ; } /* ================ end of function parse_command_line ==================== */ /*============================================================================== | write_poly | ================================================================================ DESCRIPTION Print a polynomial in a nice format. Omit terms with coefficients of zero. Suppress coefficients of 1, but not the constant term. Put every NUMTERMSPERLINE terms in the polynomial on a new line. INPUT n a[] (int *) Coefficients of the nth degree polynomial a(x) = a x + ... n + a x + a. a is stored at array location a[i], 1 0 i 0 <= i < n . n (int) The polynomial's degree. OUTPUT Standard output A pretty-printed polynomial. EXAMPLE CALLING SEQUENCE If array a[] contains a[0] = 1 a[1] = 2 a[2] = 0 a[3] = 1 and n = 3, write_poly( a, n ) prints x ^ 3 + 2 x + 1 METHOD Sheer hacking ingenuity (vulgarity?). BUGS None. -------------------------------------------------------------------------------- | Function Call | ------------------------------------------------------------------------------*/ void write_poly( int * a, int n ) { /*------------------------------------------------------------------------------ | Local Variables | ------------------------------------------------------------------------------*/ int k, /* Loop conter. */ coeff, /* Coefficient a sub k. */ first_time_through = YES, /* = NO after printing the first coefficient. */ num_terms = 0 ; /* Number of terms printed so far. */ /*------------------------------------------------------------------------------ | Function Body | ------------------------------------------------------------------------------*/ for (k = n ; k >= 0 ; --k) { /* k Print the term a x if a is nonzero. k k */ if ( (coeff = a[ k ]) != 0) { /* After the first time thorough, print leading plus signs "+" to separate the terms of the polynomial. */ if (!first_time_through) printf( " + " ) ; first_time_through = NO ; /* Always print the constant term a but print terms of higher degree 0 only if a is not 1. k */ if ( (coeff != 1) || (k == 0) ) printf( "%d", coeff ) ; /* k 1 0 Print the term x. Exceptions: print x, not x, omit x */ if (k > 1) printf( " x ^ %d", k ) ; else if (k == 1) printf( " x" ) ; /* Start a new line. */ if (++num_terms % NUMTERMSPERLINE == 0) printf( "\n" ) ; } /* end if coeff > 0 */ } /* end for */ printf( "\n" ) ; return ; } /* ======================= end of function write_poly ===================== */
