Use these templates after using namespace std;

Update Info

// Forked from Matrix_mlt[498779]
//  + Original (原生功能)
//     + Functions
//        + read()       // 2 Overloaded
//        + readchar()   // Non-overloaded
//        + write()      // Non-overloaded
// Pull Request from fengziyi[540226]
//  + Submitted (已追加功能)
//     + Functions
//        + readln()     // 2 Overloaded
//        + writespace() // 2 Overloaded
//        + writeln()    // 4 Overloaded
//     + New Buffer Reader 
//  + RePacked
//  + Unsubmitted (待完善)
//     + Float Number Reading Functions
//     + Big Interger Functions
//     + ...

Standard Version

namespace IO
{
	#define reg register
    template<typename _Tp>
    inline void read(_Tp& x)
    {
        x = 0; char c = getchar(); bool f = 0;
        while (!std::isdigit(c)) f |= c == 45, c = getchar();
        while ( std::isdigit(c)) x = x * 10 + (c ^ 48), c = getchar();
        return f ? x = -x : 1, void();
    }
    template<typename _Tp>
    inline void write(_Tp x)
    {
        static char stk[40]; int top = 0;
        if (!x)     return putchar(48), void();
        if (x < 0)  putchar(45), x = -x;
        while (x)   stk[top++] = x % 10, x /= 10;
        while (top) putchar(stk[--top] + 48);
    }
    // read
    template<typename _Tp, typename ...Args>
    inline void read(_Tp& x, Args& ...args) { read(x), read(args...); }
}
using namespace IO;

Extend Functions (Must be used with Std Ver)

namespace ExtIO
{
    // readchar
    inline void readchar(char& x) { for (x = getchar(); !std::isalpha(x); x = getchar()); }

    // readln
    template<typename _Tp, typename _Tpp>
    inline void readln(_Tp a[], _Tpp w) { for (reg _Tpp i = 1; i <= w; ++i) read(a[i]); }
    template<typename _Tp, typename _Tpp>
    inline void readln(_Tp a[], _Tpp l, _Tpp r) { for (reg _Tpp i = l; i <= r; ++i) read(a[i]); }

    // writespace
    template<typename _Tp>
    inline void writespace(_Tp x) { write(x); putchar(' '); }
    template<typename _Tp, typename ...Args>
    inline void writespace(_Tp& x, Args& ...args) { writespace(x), writespace(args...); }

    // writeln
    template<typename _Tp>
    inline void writeln(_Tp x) { write(x); putchar('\n'); }
    template<typename _Tp, typename ...Args>
    inline void writeln(_Tp& x, Args& ...args) { writespace(x), writespace(args...), putchar('\n'); }
    template<typename _Tp, typename _Tpp>
    inline void writeln(_Tp a[], _Tpp w) { for (reg _Tpp i = 1; i <= w; ++i) writespace(a[i]); putchar('\n'); }
    template<typename _Tp, typename _Tpp>
    inline void writeln(_Tp a[], _Tpp l, _Tpp r) { for (reg _Tpp i = l; i <= r; ++i) writespace(a[i]); putchar('\n'); }
};
using namespace ExtIO;

Special Buffer-Read Version

(Use flushout() at the end if writeln() is used)

卡常用，高风险

#include <cstring>
namespace bufIO
{
    const int _Pu = 1 << 16;
    const int _d = 32;
    char buf[_Pu], obuf[_Pu];
    char *inl = buf + _Pu, *inr = buf + _Pu;
    char *outl = obuf, *outr = obuf + _Pu - _d;
    inline void flushin()
    {
        memmove(buf, inl, inr - inl);
        int rlen = fread(buf + (inr - inl), 1, inl - buf, stdin);
        if (inl - rlen > buf) { buf[inr - inl + rlen] = EOF; }
        inl = buf;
    }
    inline void flushout() { fwrite(obuf, outl - obuf, 1, stdout), outl = obuf; }
    template <typename _Tp>
    inline void read(_Tp &x)
    {
        if (inl + _d > inr) { flushin(); }
        int isne = 0;
        for (; !isdigit(*inl); ++inl) { isne = (*inl == '-'); }
        x = (*inl++ - '0');
        for (; isdigit(*inl); ++inl) { x = x * 10 + (*inl - '0'); }
        if (isne) { x = -x; }
    }
    template <typename _Tp>
    inline void writeln(_Tp x, char end = '\n')
    {
        if (outl > outr) { flushout(); }
        if (x < 0) { *outl++ = '-'; x = -x; }
        char sta[20]; char *top = sta;
        do { *top++ = (x % 10) + '0'; x /= 10; } while (x);
        do { *outl++ = *--top; } while (top != sta);
        (*outl++) = end;
    }
    template<typename _Tp, typename ...Args>
    inline void read(_Tp& x, Args& ...args) { read(x), read(args...); }
}
using namespace bufIO;