快速读入快速输出

#define getchar() (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 1 << 21, stdin), p1 == p2)? EOF : *p1++)


LL in() {

    LL x = 0, f = 1; char ch;

    while(!isdigit(ch = getchar()))(ch == ‘-‘) && (f = -f);

    for(x = ch ^ 48; isdigit(ch = getchar()); x = (x << 1) + (x << 3) + (ch ^ 48));

    return x * f;

}

快速读入快速输出

原文：https://www.cnblogs.com/Vanyun/p/13382100.html