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https://github.com/tesseract-ocr/tesseract.git
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git-svn-id: https://tesseract-ocr.googlecode.com/svn/trunk@32 d0cd1f9f-072b-0410-8dd7-cf729c803f20
484 lines
15 KiB
C++
484 lines
15 KiB
C++
/* -*-C-*-
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********************************************************************************
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*
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* File: permnum.c (Formerly permnum.c)
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* Description:
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* Author: Mark Seaman, OCR Technology
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* Created: Fri Oct 16 14:37:00 1987
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* Modified: Tue Jul 2 14:12:43 1991 (Mark Seaman) marks@hpgrlt
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* Language: C
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* Package: N/A
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* Status: Reusable Software Component
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*
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* (c) Copyright 1987, Hewlett-Packard Company.
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** Licensed under the Apache License, Version 2.0 (the "License");
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** you may not use this file except in compliance with the License.
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** You may obtain a copy of the License at
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** http://www.apache.org/licenses/LICENSE-2.0
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** Unless required by applicable law or agreed to in writing, software
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** distributed under the License is distributed on an "AS IS" BASIS,
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** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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** See the License for the specific language governing permissions and
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** limitations under the License.
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*
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*********************************************************************************/
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/*----------------------------------------------------------------------
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I n c l u d e s
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----------------------------------------------------------------------*/
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#include "const.h"
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#include "permnum.h"
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#include "debug.h"
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#include "permute.h"
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#include "dawg.h"
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#include "tordvars.h"
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#include "stopper.h"
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#include <math.h>
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#include <ctype.h>
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/*----------------------------------------------------------------------
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V a r i a b l e s
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----------------------------------------------------------------------*/
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static const char *allowed_alpha_strs[] = {
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"jan", "feb", "mar", "apr", "may", "jun",
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"jul", "aug", "sep", "oct", "nov", "dec", NULL
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};
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static const char *allowed_char_strs[] = {
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"adfjmnos", "aceopu", "bcglnrptvy"
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};
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const int kNumStates = 7;
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static int number_state_table[kNumStates][8] = { {
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/* 0. Beginning of string */
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/* l d o a t 1 2 3 */
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0, 1, 1, -99, -99, 4, -99, -99
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},
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{ /* 1. After a digit or operator */
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-99, 1, 1, 3, 2, 4, 3, 3
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},
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{ /* 2. After trailing punctuation */
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-99, -99, 1, -99, 2, -99, -99, -99
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},
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{ /* 3. After a alpha character */
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-99, -99, 3, 3, 2, 3, 3, 3
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},
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{ /* 4. After 1st char */
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-99, -1, -1, -99, -2, -99, 5, -99
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},
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{ /* 5. After 2nd char */
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-99, -1, -1, -99, -2, -99, -99, 6
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},
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{ /* 6. After 3rd char */
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-99, -1, -1, -99, -2, -99, -99, -99
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}
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};
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// The state is coded with its true state shifted left by kStateShift.
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// A repeat count (starting with 0) is stored in the lower bits
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// No state is allowed to occur more than kMaxRepeats times.
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const int kStateShift = 4;
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const int kRepeatMask = (1 << kStateShift) - 1;
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const int kMaxRepeats[kNumStates] = {
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3, 10, 3, 3, 3, 3, 3
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};
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make_float_var (good_number, GOOD_NUMBER, make_good_number,
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8, 15, set_good_number, "Good number adjustment");
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make_float_var (ok_number, OK_NUMBER, make_ok_number,
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8, 16, set_ok_number, "Bad number adjustment");
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make_toggle_var (number_debug, 0, make_number_debug,
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8, 23, set_number_debug, "Number debug");
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make_int_var (number_depth, 3, make_number_depth,
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8, 24, set_number_depth, "Number depth");
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/*----------------------------------------------------------------------
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M a c r o s
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----------------------------------------------------------------------*/
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/**********************************************************************
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* isleading
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*
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* Return non-zero if this is a leading type punctuation mark for the
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* numeric grammar.
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**********************************************************************/
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#define isleading(ch) \
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((ch == '{' ) || \
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(ch == '[' ) || \
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(ch == '(' ) || \
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(ch == '#' ) || \
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(ch == '@' ) || \
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(ch == '$' ))
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/**********************************************************************
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* istrailing
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*
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* Return non-zero if this is a leading type punctuation mark for the
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* numeric grammar.
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**********************************************************************/
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#define istrailing(ch) \
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((ch == '}' ) || \
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(ch == ']' ) || \
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(ch == ')' ) || \
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(ch == ';' ) || \
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(ch == ':' ) || \
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(ch == ',' ) || \
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(ch == '.' ) || \
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(ch == '%' ))
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/**********************************************************************
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* isoperator
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*
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* Return non-zero if this is a leading type punctuation mark for the
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* numeric grammar.
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**********************************************************************/
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#define isoperator(ch) \
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((ch == '*' ) || \
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(ch == '+' ) || \
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(ch == '-' ) || \
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(ch == '/' ) || \
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(ch == '.' ) || \
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(ch == ':' ) || \
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(ch == ',' ))
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/*----------------------------------------------------------------------
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F u n c t i o n s
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----------------------------------------------------------------------*/
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/**********************************************************************
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* adjust_number
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*
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* Assign an adjusted value to a string that is a word. The value
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* that this word choice has is based on case and punctuation rules.
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**********************************************************************/
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void adjust_number(A_CHOICE *best_choice, float *certainty_array) {
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float adjust_factor;
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if (adjust_debug)
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cprintf ("Number: %s %4.2f ",
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class_string (best_choice), class_probability (best_choice));
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class_probability (best_choice) += RATING_PAD;
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if (pure_number (class_string (best_choice))) {
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class_probability (best_choice) *= good_number;
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adjust_factor = good_number;
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if (adjust_debug)
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cprintf (", %4.2f ", good_number);
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}
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else {
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class_probability (best_choice) *= ok_number;
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adjust_factor = ok_number;
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if (adjust_debug)
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cprintf (", N, %4.2f ", ok_number);
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}
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class_probability (best_choice) -= RATING_PAD;
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LogNewWordChoice(best_choice, adjust_factor, certainty_array);
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if (adjust_debug)
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cprintf (" --> %4.2f\n", class_probability (best_choice));
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}
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/**********************************************************************
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* append_number_choices
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*
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* Check to see whether or not the next choice is worth appending to
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* the string being generated. If so then keep going deeper into the
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* word.
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**********************************************************************/
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void append_number_choices(int state,
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char *word,
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CHOICES_LIST choices,
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int char_index,
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A_CHOICE *this_choice,
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float *limit,
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float rating,
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float certainty,
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float *certainty_array,
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CHOICES *result) {
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int word_ending = FALSE;
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int x;
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if (char_index == (array_count (choices) - 1))
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word_ending = TRUE;
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word[char_index] = class_string (this_choice)[0];
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word[char_index + 1] = '\0';
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if (word[char_index] == '\0')
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word[char_index] = ' ';
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certainty_array[char_index] = class_certainty (this_choice);
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rating += class_probability (this_choice);
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certainty = min (class_certainty (this_choice), certainty);
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if (rating < *limit) {
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state = number_state_change (state, word + char_index);
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if (number_debug)
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cprintf ("%-20s prob=%4.2f state=%d\n", word, rating, state);
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if (state != -1) {
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if ((state >> kStateShift) == 3 &&
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char_index + 3 < array_count (choices)) {
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return;
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}
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if (word_ending) {
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for (x = 0; x <= char_index; x++) {
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if (isdigit (word[x])) {
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if (number_debug)
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cprintf ("new choice = %s\n", word);
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push_on (*result, new_choice (word, rating, certainty,
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-1, NUMBER_PERM));
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adjust_number ((A_CHOICE *) first_node (*result),
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certainty_array);
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if (best_probability (*result) > *limit) {
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free_choice (first_node (*result));
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pop_off(*result);
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}
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else {
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*limit = best_probability (*result);
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break;
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}
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}
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}
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}
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else {
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JOIN_ON (*result,
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number_permute (state, choices, char_index + 1, limit,
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word, rating, certainty,
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certainty_array));
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}
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}
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}
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else {
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if (number_debug)
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cprintf ("pruned word (%s, rating=%4.2f, limit=%4.2f)\n",
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word, rating, *limit);
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}
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}
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/**********************************************************************
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* init_permute
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*
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* Initialize anything that needs to be set up for the permute
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* functions.
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**********************************************************************/
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void init_permnum() {
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make_good_number();
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make_ok_number();
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make_number_debug();
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make_number_depth();
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}
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/**********************************************************************
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* number_character_type
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*
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* Decide which type of a character (with regard to the numeric state
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* table) we are looking at.
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**********************************************************************/
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int number_character_type( //current state
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char ch,
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int state) {
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char lower_char = tolower (ch);
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if (isalpha (ch)) {
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if (state < 4 && strchr (allowed_char_strs[0], lower_char) != NULL)
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return 5;
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else if (state == 4
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&& strchr (allowed_char_strs[1], lower_char) != NULL)
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return 6;
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else if (state == 5
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&& strchr (allowed_char_strs[2], lower_char) != NULL)
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return 7;
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return 3;
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}
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else if (isdigit (ch))
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return (1);
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else if (isoperator (ch))
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return (2);
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else if (istrailing (ch))
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return (4);
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else if (isleading (ch))
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return (0);
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else
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return (-1);
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}
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/**********************************************************************
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* number_state_change
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*
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* Execute a state transition according to the state table and
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* additional rules.
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**********************************************************************/
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int number_state_change(int state, //current state
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const char *word) { //current char
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int char_type; //type of char
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int new_state; //state to return
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int old_state = state >> kStateShift;
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int repeats = state & kRepeatMask;
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int index;
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char copy_word[4]; //tolowered chars
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char_type = number_character_type (*word, old_state);
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if (char_type == -1)
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return -1;
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new_state = number_state_table[old_state][char_type];
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if (new_state == old_state) {
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++repeats;
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if (repeats >= kMaxRepeats[old_state])
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return -1;
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} else {
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repeats = 0;
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}
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if (new_state >= 0)
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return (new_state << kStateShift) | repeats;
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if (new_state == -99)
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return -1;
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//now check to see if the last state-3 chars in the word
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//make an allowable word. For now only 3 letter words
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//are allowed
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if (old_state != 6)
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return -1; //only 3 letters now
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copy_word[0] = tolower (word[-3]);
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copy_word[1] = tolower (word[-2]);
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copy_word[2] = tolower (word[-1]);
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copy_word[3] = '\0';
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for (index = 0; allowed_alpha_strs[index] != NULL; index++) {
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if (strcmp (copy_word, allowed_alpha_strs[index]) == 0)
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return (-new_state) << kStateShift;
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}
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return -1; //not a good word
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}
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/**********************************************************************
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* number_permute
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*
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* Permute all the valid string that match the 'grammar' of numbers.
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* The valid syntax for numbers is encoded in a state table. The
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* permuter uses this state table to enumerate all the string that
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* can be produced using the input choices.
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**********************************************************************/
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CHOICES number_permute(int state,
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CHOICES_LIST choices,
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int char_index,
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float *limit,
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char *word,
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float rating,
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float certainty,
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float *certainty_array) {
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CHOICES result = NIL;
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CHOICES c;
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int depth = 0;
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if (number_debug) {
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cprintf ("number_permute (state=%d, char_index=%d, limit=%4.2f, ",
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state, char_index, *limit);
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cprintf ("word=%s, rating=%4.2f, certainty=%4.2f)\n",
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word, rating, certainty);
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}
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if (char_index < array_count (choices)) {
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iterate_list (c, (CHOICES) array_index (choices, char_index)) {
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if (depth++ < number_depth)
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append_number_choices (state, word, choices, char_index,
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(A_CHOICE *) first_node (c), limit, rating,
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certainty, certainty_array, &result);
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}
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}
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if (result && number_debug == 1)
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print_choices ("number_permute:", result);
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return (result);
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}
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/**********************************************************************
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* number_permute_and_select
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*
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* Permute all the possible valid numbers and adjust their ratings.
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* Save the best rating.
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**********************************************************************/
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A_CHOICE *number_permute_and_select(CHOICES_LIST char_choices,
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float rating_limit) {
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CHOICES result = NIL;
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char word[MAX_WERD_LENGTH + 1];
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float certainty_array[MAX_WERD_LENGTH + 1];
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float rating = rating_limit;
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A_CHOICE *best_choice;
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best_choice = new_choice (NULL, MAXFLOAT, -MAXFLOAT, -1, NO_PERM);
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if (array_count (char_choices) <= MAX_WERD_LENGTH) {
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word[0] = '\0';
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result = number_permute (0, char_choices, 0, &rating,
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word, 0.0, 0.0, certainty_array);
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if (display_ratings && result)
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print_choices ("number_permuter", result);
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while (result != NIL) {
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if (best_probability (result) < class_probability (best_choice)) {
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clone_choice (best_choice, first_node (result));
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}
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free_choice (first_node (result));
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pop_off(result);
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}
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}
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return (best_choice);
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}
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/**********************************************************************
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* pure_number
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*
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* Check to see if this string is a pure number (one that does not end
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* with alphabetic characters).
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**********************************************************************/
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int pure_number(const char *string) {
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int x;
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for (x = strlen (string) - 1; x >= 0; x--) {
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if (isdigit (string[x])) {
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return (TRUE);
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}
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else if (isalpha (string[x]))
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return (FALSE);
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}
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return (FALSE);
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}
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/**********************************************************************
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* valid_number
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*
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* Check this string to see if it is a valid number. Return TRUE if
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* it is.
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**********************************************************************/
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int valid_number(const char *string) {
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int state = 0;
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int char_index;
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int num_chars = strlen (string);
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int num_digits = 0;
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for (char_index = 0; char_index < num_chars; char_index++) {
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state = number_state_change (state, string + char_index);
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if (state == -1)
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return (FALSE);
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if (isdigit (string[char_index]))
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num_digits++;
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}
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return num_digits > num_chars - num_digits;
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}
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