快读

参考：​​算法笔记--快读（输入外挂）模板​​

基础版本：

inline int read(){  
   int s=0,w=1;  
   char ch=getchar();  
   while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}  
   while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();  
   return s*w;  
}
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';
}

进阶版：

struct FastIO {
    static const int S = 4e6;
    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 = fread(buf, 1, S, stdin);
        if (pos == len) exit(0);
        return buf[pos++];
    }
    inline int xuint() {
        int c = xchar(), x = 0;
        while (c <= 32) c = xchar();
        for (; '0' <= c && c <= '9'; c = xchar()) x = x * 10 + c - '0';
        return x;
    }
    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;
    }
    inline void xstring(char *s)
    {
        int c = xchar();
        while (c <= 32) c = xchar();
        for (; c > 32; c = xchar()) * s++ = c;
        *s = 0;
    }
    inline void wchar(int x)
    {
        if (wpos == S) fwrite(wbuf, 1, S, stdout), wpos = 0;
        wbuf[wpos++] = x;
    }
    inline void wint(int x)
    {
        if (x < 0) wchar('-'), x = -x;
        char s[24];
        int n = 0;
        while (x || !n) s[n++] = '0' + x % 10, x /= 10;
        while (n--) wchar(s[n]);
        wchar('\n');
    }
    inline void wstring(const char *s)
    {
        while (*s) wchar(*s++);
    }
    ~FastIO()
    {
        if (wpos) fwrite(wbuf, 1, wpos, stdout), wpos = 0;
    }
} io;
/*
输入：io.xint(); io.xchar(); io.xstring(s);
输出：io.wint(x); io.wchar(x); io.wstring(s);
*/

多组输入：

const int BUF = 25000000;
char Buf[BUF],*buf=Buf;
inline void read(int &a)
{
    for(a=0;*buf<48;buf++);
    while(*buf>47) a=a*10+*buf++-48;
}

int tot = fread(Buf, 1, BUF, stdin);
while(true) {
        if(buf-Buf+1 >= tot) break;
}

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