roman.cpp

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/******************************************************************************
 *
 *  roman.cpp - 
 *
 * $Id: roman.cpp 3754 2020-07-10 17:45:48Z scribe $
 *
 * Copyright 2002-2013 CrossWire Bible Society (http://www.crosswire.org)
 *  CrossWire Bible Society
 *  P. O. Box 2528
 *  Tempe, AZ  85280-2528
 *
 * 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 version 2.
 *
 * 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.
 *
 */

#include <stdlib.h>
#include <string.h>
#include <roman.h>


SWORD_NAMESPACE_START


char isRoman(const char *str, int maxchars) {
    char *ch = (char*)str;
    for (; *ch && (!maxchars || (ch-str) <= maxchars); ch++)
        if (!strchr("IVXLCDMivxlcdm ", *ch))
            return 0;
    return 1;
}

int fromRoman(const char* str) {
    int i, n = (int)strlen(str);
    short * num= (short *) calloc(n, sizeof(short));
    for (i = 0; str[i]; i++) {
        switch(str[i]) {
        case 'i':
        case 'I':
            num[i] = 1;
            break;
        case 'v':
        case 'V':
            num[i] = 5;
            break;
        case 'x':
        case 'X':
            num[i] = 10;
            break;
        case 'l':
        case 'L':
            num[i] = 50;
            break;
        case 'c':
        case 'C':
            num[i] = 100;
            break;
        case 'd':
        case 'D':
            num[i] = 500;
            break;
        case 'm':
        case 'M':
            num[i] = 1000;
            break;
        default:
            num[i] = 0;
        }
    }
    for (i = 1; str[i]; i++) {
        if (num[i] > num[i-1])  {
            num[i] -= num[i-1];
            num[i-1] = 0;
        }
    }
    n = 0;
    for (i = 0; str[i]; i++) {
        n += num[i];
    }

    free(num);

    return n;
}


SWORD_NAMESPACE_END