/*  restrict.c  --  skip restriction  (corrected formulas)  */

#include <stdlib.h>
#include <ctype.h>
#include <math.h>
#include "ios.h"   /* using the input/output service module  */

#define DESIRED 10.0

#define ERR_LINE 1
#define ERR_REPEAT 2

static long int  Table [256];
static long int  Total;

void  calculation (
    double n,
    double L,
    double prob,
    double desired,
    int * restricted,
    long int * restriction,
    double * expected
 );

void  main ( int argc, char * argv [] )
{    int c, k, n;  char cc;  long int N;
     char * from;  FILE * outfile;
     double  prob, expected;
     long int  restriction;
     int  restricted;
 if ( argc < 4 )  err_command_line ( "restrict frequencies words outfile" );
 open_input_file ( argv [1] );
 for ( c=0; c<256; c++ )  Table [c] = 0;
 Total = 0;
 while ( 0 <= get_line ( & from ) ) {
   if ( 2 != sscanf ( from, " %c %ld", &cc, &N ) ) {
     printf ( "wrong input line [%s]\n", from );
     exit ( ERR_LINE );
   }
   c = (unsigned char) cc;
   if ( Table [c] ) {
     printf ( "repeated letter: [%s]\n", from );
     exit ( ERR_REPEAT );
   }
   Table [c] = N;
   Total += N;
 }
 open_input_file ( argv [2] );
 outfile = open_output_file ( argv [3] );
 while ( 0 <= ( n = get_line ( & from ) ) ) {
   while ( n > 0 ) {
     c = (unsigned char) *from;
     if ( ( c & 0x80 ) || ! isascii (c) || ! isspace (c) )  break;
     ++ from;
     -- n;
   }
   while ( n > 0 ) {
     c = (unsigned char) from [n-1];
     if ( ( c & 0x80 ) || ! isascii (c) || ! isspace (c) )  break;
     -- n;
   }
   if ( n < 2 ) {
     printf ( "warning: word [ %s ] is too short\n", from );
     continue;
   }
   prob = 1.0;
   for ( k=0; k<n; k++ ) {
     c = (unsigned char) from [k];
     prob *= (double) Table [c] / (double) Total;
   }
   if ( prob == 0.0 ) {
     printf ( "warning: word [ %s ] does not fit\n", from );
     continue;
   }
   calculation ( (double) n, (double) Total, prob, DESIRED,
                 & restricted, & restriction, & expected );
   fprintf ( outfile, "[ " );
   for ( k=0; k<n; k++ )
     fprintf ( outfile, "%c", from [k] );
   for ( k=n; k<15; k++ )
     fprintf ( outfile, " " );
   fprintf ( outfile, " %6ld ", restriction );
   if ( restricted) fprintf ( outfile, " restricted " );
   else             fprintf ( outfile, "unrestricted" );
   fprintf ( outfile, " %4.1f ]\n", expected );
 }
 exit (0);
}

void  calculation (
    double n,
    double L,
    double prob,
    double desired,
    int * restricted,
    long int * restriction,
    double * expected
  )
 {   double  discrim, b, n1, D;  int flag;
 n1 = n - 1.0;
 b = L - 1.5 * n1;
 discrim = b * b - desired * n1 / prob;
 if ( discrim < 0.0 ) {
   flag = 0;
   D =  L / n1;
 } else {
   flag = 1;
   D = ( L - 0.5 * n1 - sqrt (discrim) ) / n1;
 }
 * restricted = flag;
 D = (long int) D;
 if ( D > floor ( L / n1 ) )  D = floor ( L / n1 );
 * restriction = (long int) D;
 * expected = prob *
    2.0 * ( D - 1.0 ) * ( L - n1 * ( 2.0 + D ) * 0.5 );
}

/*  end of  restrict.c  */