快读knowledge

 1 #define R register
 2 #define getc() (S == T && (T = (S = B) + fread(B, 1, 1 << 15, stdin), S == T) ? EOF : *S++)
 3 #define dmax(_a, _b) ((_a) > (_b) ? (_a) : (_b))
 4 #define dmin(_a, _b) ((_a) < (_b) ? (_a) : (_b))
 5 #define cmax(_a, _b) (_a < (_b) ? _a = (_b) : 0)
 6 #define cmin(_a, _b) (_a > (_b) ? _a = (_b) : 0)
 7 #define cabs(_x) ((_x) < 0 ? (- (_x)) : (_x))
 8 char B[1 << 15], *S = B, *T = B;
 9 inline int F()
10 {
11     R char ch; R int cnt = 0; R bool minus = 0;
12     while (ch = getc(), (ch < ‘0‘ || ch > ‘9‘) && ch != ‘-‘) ;
13     ch == ‘-‘ ? minus = 1 : cnt = ch - ‘0‘;
14     while (ch = getc(), ch >= ‘0‘ && ch <= ‘9‘) cnt = cnt * 10 + ch - ‘0‘;
15     return minus ? -cnt : cnt;
16 }
17 #define maxn 110