acm 10494 if we were a child again，小學數學

first = 1;  
if (ch[0] == '/')
{
    tmp = 0;
    for (i = 0; (c = m[i]); i ++)
    {
        tmp *= b;
        tmp += c - '0';
        j = tmp / n;
        if (j != 0) first = 0;
        if (!first) printf("%lld", j);
        tmp %= n;
    }
    if (first) printf("0");
    printf("n");
}
if (ch[0] == '%')
{
    for (i = 0, tmp = 0; (c = m[i]); i ++)
    {
        tmp *= b;
        tmp += c - '0';
        tmp %= n;
    }
    printf("%lldn", tmp);
}