模板汇总——快读 fread

　　

 struct FastIO {
     static const int S = ;
     int wpos;
     char wbuf[S];
     FastIO() : wpos() { }
     inline int xchar() {
         static char buf[S];
         static int len = , pos = ;
         if (pos == len) pos = , len = fread(buf, , S, stdin);
         if (pos == len) return -;
         return buf[pos++];
     }
     inline int xint() {
         int c = xchar(), x = , s = ;
         while (c <= ) c = xchar();
         if (c == '-') s = -, c = xchar();
         for (; '' <= c && c <= ''; c = xchar()) x = x *  + c - '';
         return x * s;
     }
     ~FastIO() {
         if (wpos) fwrite(wbuf, , wpos, stdout), wpos = ;
     }
 } io;