快读板子

template<class T>
void read(T &res)
{
    res = 0;
    char c = getchar();
    T f = 1;
    while(c < '0' || c > '9')
    {
        if(c == '-') f = -1;
        c = getchar();
    }
    while(c >= '0' && c <= '9')
    {
        res = res * 10 + c - '0';
        c = getchar();
    }
    res *= f;
}