读入读出挂！！

说起读入读出挂，体内洪荒之力呼啸飞过，输入输出规模超过 10e6 就可以用啦；

参考博客：https://blog.csdn.net/f_zyj/article/details/51473493

适用于正整数

void read(int &x){
    char ch = getchar();x = 0;
    for (; ch < '0' || ch > '9'; ch = getchar());
    for (; ch >='0' && ch <= '9'; ch = getchar()) x = x * 10 + ch - '0';
}

template <class T>
inline void scan_d(T &ret) 
{
    char c; 
    ret = 0;
    while ((c = getchar()) < '0' || c > '9');
    while (c >= '0' && c <= '9')
    { 
        ret = ret * 10 + (c - '0'), c = getchar();
    }
}

适用于正负整数

template <class T>
inline bool scan_d(T &ret) 
{
    char c; 
    int sgn;
    if (c = getchar(), c == EOF) 
    {
        return 0; //EOF 
    }
    while (c != '-' && (c < '0' || c > '9')) 
    {
        c = getchar(); 
    }
    sgn = (c == '-') ? -1 : 1;
    ret = (c == '-') ? 0 : (c - '0'); 
    while (c = getchar(), c >= '0' && c <= '9') 
    {
        ret = ret * 10 + (c - '0'); 
    }
    ret *= sgn;
    return 1;
}

template <class T>
inline void print_d(T x) 
{ 
    if (x > 9) 
    {
        print_d(x / 10); 
    }
    putchar(x % 10 + '0');
}

仅适合纯数字输入输出

int Scan()
{   //  输入外挂  
    int res = 0, flag = 0;  
    char ch;  
    if ((ch = getchar()) == '-') 
    {   
        flag = 1;  
    }    
    else if(ch >= '0' && ch <= '9') 
    {
        res = ch - '0'; 
    }
    while ((ch = getchar()) >= '0' && ch <= '9')  
    {
        res = res * 10 + (ch - '0');  
    }
    return flag ? -res : res;  
}  

void Out(int a) 
{   //  输出外挂  
    if (a < 0) 
    {
        putchar('-');
        a = -a;
    }  
    if (a >= 10)
    {
       Out(a / 10);  
    }
    putchar(a % 10 + '0');  
}  

int main() 
{  
    int T, n;  
    scanf ("%d", &T);  
    while (T--) 
    {  
        n = Scan();  
        Out(n);  
        printf("
");  
    }  
    return 0;  
}

适用于正负数(int,long long,float,double)

template <class T>
bool scan_d(T &ret)
{
    char c; 
    int sgn; 
    T bit = 0.1;
    if (c=getchar(), c==EOF) 
    {
        return 0;
    }
    while (c! = '-' && c != '.' && (c < '0' || c > '9')) 
    {
        c = getchar();
    }
    sgn = (c == '-') ? -1 : 1;
    ret = (c == '-') ? 0 : (c - '0');
    while (c = getchar(), c >= '0' && c <= '9')
    {
        ret = ret * 10 + (c - '0');
    }
    if (c == ' ' || c == '
')
    {
        ret *= sgn;
        return 1;
    }
    while (c = getchar(), c >= '0' && c <= '9')
    {
        ret += (c - '0') * bit, bit /= 10;
    }
    ret *= sgn;
    return 1;
}

template <class T>
inline void print_d(int x)
{
    if (x > 9)
    {
        print_d(x / 10);
    }
    putchar(x % 10 + '0');
}

套装

char buf[MAXIN], *ps = buf, *pe = buf + 1;

inline void rnext()
{
    if (++ps == pe)
    {
        pe = (ps = buf) + fread(buf, sizeof(char), sizeof(buf) / sizeof(char), stdin);
    }
    return ;
}

template <class T>
inline bool in(T &ans)
{
    ans = 0;
    T f = 1;
    if (ps == pe)
    {
        return false;
    }
    do
    {
        rnext();
        if ('-' == *ps)
        {
            f = -1;
        }
    } while (!isdigit(*ps) && ps != pe);
    if (ps == pe)
    {
        return false;
    }
    do
    {
        ans = (ans << 1) + (ans << 3) + *ps - 48;
        rnext();
    } while (isdigit(*ps) && ps != pe);
    ans *= f;
    return true;
}

char bufout[MAXOUT], outtmp[50], *pout = bufout, *pend = bufout + MAXOUT;

inline void write()
{
    fwrite(bufout, sizeof(char), pout - bufout, stdout);
    pout = bufout;
    return ;
}

inline void out_char(char c)
{
    *(pout++) = c;
    if (pout == pend)
    {
        write();
    }
    return ;
}

inline void out_str(char *s)
{
    while (*s)
    {
        *(pout++) = *(s++);
        if (pout == pend)
        {
            write();
        }
    }
    return ;
}

template <class T>
inline void out_int(T x)
{
    if (!x)
    {
        out_char('0');
        return ;
    }
    if (x < 0)
    {
        x = -x, out_char('-');
    }
    int len = 0;
    while (x)
    {
        outtmp[len++] = x % 10 + 48;
        x /= 10;
    }
    outtmp[len] = 0;
    for (int i = 0, j = len - 1; i < j; i++, j--)
    {
        swap(outtmp[i], outtmp[j]);
    }
    out_str(outtmp);
    return ;
}

更加高效的输入输出外挂

struct FastIO
{
    static const int S = 100 << 1;

    int wpos;
    char wbuf[S];

    FastIO() : wpos(0) {}

    inline int xchar()
    {
        static char buf[S];
        static int len = 0, pos = 0;

        if (pos == len)
        {
            pos = 0;
            len = (int)fread(buf, 1, S, stdin);
        }
        if (pos == len)
        {
            return -1;
        }

        return buf[pos++];
    }

    inline int xint()
    {
        int s = 1, c = xchar(), x = 0;
        while (c <= 32)
        {
            c = xchar();
        }
        if (c == '-')
        {
            s = -1;
            c = xchar();
        }
        for (; '0' <= c && c <= '9'; c = xchar())
        {
            x = x * 10 + c - '0';
        }

        return x * s;
    }

    ~FastIO()
    {
        if (wpos)
        {
            fwrite(wbuf, 1, wpos, stdout);
            wpos = 0;
        }
    }
} io;