use Inline C => <<'__EOC__';

SV *fast_c (char *original, char *chopped) {
        int counts[256] = {0};  /* each potential character */
        int ptr = 0;
        int buffer_size = 0;
        char *ret = NULL;
        int ret_ptr = 0;
        int error = 0;
        SV *retsv = &PL_sv_undef;

        while (original[ptr] != '\0') {
                counts[original[ptr++]]++;
                buffer_size++;
        }

        ptr = 0;

        while (!error && chopped[ptr] != '\0') {
                counts[chopped[ptr]]--;
                buffer_size--;
                if (counts[chopped[ptr++]] < 0) {
                        error++;
                }
        }

        if (!error) {
                ret = malloc(buffer_size + 1);
                for (ptr = 0; ptr <= 255; ptr++) {
                        while (counts[ptr]-- > 0) {
                                ret[ret_ptr++] = ptr;
                        }
                }
                ret[ret_ptr] = '\0';
                retsv = newSVpvn(ret, strlen(ret));
                free(ret);
        }

        return(retsv);
}

__EOC__