快读
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('
');
}
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;
}