/*
    第２種情報処理技術者試験    平成6年度・春期・午後 問13
                                BohYoh Shibata PREPARATION
*/

#include <stdio.h>
#include <string.h>
#define  BUFSIZE   80
#define  TRUE       1
#define  FALSE      0

int rdxcnv(char *, unsigned long *);
int numchk(char *, char *);

main()
{
    char buff[BUFSIZE];
    int  rv = TRUE;
    unsigned long mem = 0L;
    enum {DEC, HEX, OCT }  radix = DEC ;

    for (;;) {
        fputs(">", stdout);
        fgets(buff, BUFSIZE, stdin);
        buff[strlen(buff) - 1] = '\0' ;         /* 改行文字添削 */
        if (strcmp(buff, "END") == 0)
            break;
        else if (strcmp(buff, "DEC") == 0)
            radix = DEC;
        else if (strcmp(buff, "HEX") == 0)
            radix = HEX;
        else if (strcmp(buff, "OCT") == 0)
            radix = OCT;
        else
            rv = rdxcnv(buff, &mem) ;
        if (rv == FALSE) {
            fputs("EOOR!!!\n", stdout);
            rv = TRUE;
        } else {
            switch (radix) {
              case DEC:
                fprintf(stdout, "%lu DEC\n", mem);
                break;
              case HEX:
                fprintf(stdout, "%lX HEX\n", mem);
                break;
              case OCT:
                fprintf(stdout, "%lo OCT\n", mem);
                break;
            }
        }
    }
}

int rdxcnv(char *buff, unsigned long *memp)
{
    int  rv;

    if (strlen(buff) < 2)
        return FALSE ;
    switch (buff[0]) {
      case 'D':
        rv = numchk(buff+1, "0123456789");
        if (rv == TRUE)
            sscanf( buff + 1 , "%lu",  memp );
        break;
      case 'H':
        rv = numchk(buff+1, "0123456789ABCDEF");
        if (rv == TRUE)
            sscanf( buff + 1 , "%lX",  memp );
        break;
      case 'O':
        rv = numchk(buff+1, "01234567");
        if (rv == TRUE)
            sscanf( buff + 1 , "%lo",  memp );
        break;
      default:
        rv = FALSE;
    }
    return rv;
}

int numchk(char *buff, char *base)
{
    int  m, n;

    for (m = 0; buff[m] != '\0'; m++) {
        for (n = 0; base[n] != '\0'; n++)
            if (buff[m] == base[n])
                break;
            if ( base[n] == '\0' )
                return FALSE;
    }
    return TRUE;
}