快读快写板子

假快读：

比 cin 快，比 scanf 优雅，比 read 好写，

namespace fira {
    struct IO { } io; inline void print(char x) {putchar(x);}
    template <typename T> inline void read(T &x) {scanf("%d", &x);}
    template <typename T> inline void print(T x) {printf("%d", x);}
    template <typename T> IO &operator>>(IO &a, T &x) {return read(x), a;}
    template <typename T> IO &operator<<(IO &a, T x) {return print(x), a;}
} using namespace fira;

这是真快读了：

在 linux 环境下可用 getchar_unlocked，速度与 fread 大致相同，

namespace fira {
    #ifndef _WIN32
        #define getchar getchar_unlocked
        #define putchar putchar_unlocked
    #endif
    struct IO { } io;
    template <typename T> inline void read(T &x) {
        x = 0; int f = 1; char ch = getchar();
        while (ch< '0'  or ch> '9') { if (ch == '-') f = -1; ch = getchar(); }
        while (ch>='0' and ch<='9') x=(x<<3)+(x<<1)+(ch^48), ch = getchar();
        x *= f;
    }
    template <typename T> inline void print(T x) {
        static char t[20]; int top = 0;
        if (x < 0) putchar('-'), x = -x;
        do { t[++top] = x % 10, x /= 10; } while (x);
        while (top) putchar(t[top--] + 48);
    }
    inline void print(char x) { putchar(x); }
    template <typename T> IO &operator>>(IO &a, T &x) { return read(x), a; }
    template <typename T> IO &operator<<(IO &a, T x) { return print(x), a; }
}
using namespace fira;