文件式快速读取

ACM-ICPC速度最快的读取方式，没有之一。

struct reader
{
    const int MAXBUF = 1 << 20;
    char buf[1<<20], *fh=NULL, *ft=NULL;
    inline char gc() 
    {
        if(fh == ft) 
        {
            int l = fread(buf, 1, MAXBUF, stdin);
            ft = (fh = buf) + l;
        }
        return *fh++;
    }

    inline int read() 
    {
        int x = 0;
        char c = gc();
        for(; c < '0' || c > '9'; c = gc())
            ;
        for(; c >= '0' && c <= '9'; c = gc())
            x = (x << 3) + (x << 1) + c - '0';
        return x ;
    }
    inline void _write(long long x) 
    {
        if(x > 9)
            _write(x / 10);
        putchar(x % 10 + '0');
    }
    inline void write(long long x) 
    {
        _write(x);
        putchar('
');
    }
};
reader r;