fastIO
a___
2020-10-06 16:29:10
整形快读（不定参，c++11）
```cpp
#include<cstdio>
char getch()
{
static const int N=1e6;
static char buf[N+10],*p1=NULL,*p2=NULL;
return (p1==p2)&&(p2=(p1=buf)+fread(buf,1,N,stdin),p1==p2)?EOF:*p1++;
}
void putch(char c)
{
#define flush() fwrite(buf,1,len,stdout),len=0
static const int N=1e6;
static char buf[N+10];
static int len=0;
if(c==EOF)flush();
else buf[len++]=c;
if(len==N)flush();
#undef flush
}
void readint(){}
template<typename T,typename ...Tr>
void readint(T &a,Tr&... rest)
{
a=0;bool f=false;char ch;
while(ch=getch(),ch<'0'||ch>'9')f=ch=='-';
do a=a*10+ch-'0',ch=getch(); while(ch>='0'&&ch<='9');
if(f)a=-a;
readint(rest...);
}
template<typename T>
void writeaninteger(T a)
{
static char buf[20],len=0;
if(a<0)putch('-'),a=-a;
do buf[len++]=a%10+'0',a/=10; while(a);
while(len)putch(buf[--len]);
}
template<const char end='\n',const char split=' ',typename T>
void writeint(T a)
{
writeaninteger(a);
if(end)putch(end);
}
template<const char end='\n',const char split=' ',typename T,typename ...Tr>
void writeint(T a,Tr... rest)
{
writeaninteger(a);
if(split)putch(split);
writeint<end,split>(rest...);
}
int main()
{
int a;long long b;
readint(a,b);
writeint<' ','\r'>(a,b,999);
putch(EOF);
return 0;
}
```
重载快读（附带几个常用类型）
```cpp
#include<cstdio>
namespace qio
{
class istream
{
private:
FILE *fin;
static const int N=1e6;
char buf[N+10],*p1=NULL,*p2=NULL;
protected:
inline char getchar(void){return (p1==p2)&&(p2=(p1=buf)+fread(buf,1,N,fin),p1==p2)?EOF:*p1++;}
template<typename T>
void readint(T &a)
{
a=0;bool f=false;char ch;
while(ch=getchar(),ch<'0'||ch>'9')f=ch=='-';
do a=a*10+ch-'0',ch=getchar(); while(ch>='0'&&ch<='9');
if(f)a=-a;
}
inline void readstr(char *p)
{
do *p=getchar(); while(*p<=32);
do *++p=getchar(); while(*p>32);
*p='\0';
}
public:
istream():fin(NULL){}
istream(FILE *f):fin(f){}
istream(const char *name):fin(fopen(name,"r")){}
template<typename T>
istream& operator>> (T &a){readint(a);return *this;}
istream& operator>> (char &c){c=getchar();return *this;}
istream& operator>> (char *s){readstr(s);return *this;}
};
class ostream
{
private:
FILE *fout;
static const int N=1e6;
char buf[N+10];int len;
protected:
inline void flush(){fwrite(buf,1,len,fout),len=0;}
inline void putchar(char c){buf[len++]=c;if(len==N)flush();}
template<typename T>
void writeint(T a)
{
char buf[20],len=0;
if(a<0)putchar('-'),a=-a;
do buf[len++]=a%10+'0',a/=10; while(a);
while(len)putchar(buf[--len]);
}
inline void writestr(const char *s){for(int i=0;s[i];++i)putchar(s[i]);}
public:
ostream():fout(NULL){}
ostream(FILE *f):fout(f){}
ostream(const char *name):fout(fopen(name,"w")){}
~ostream(){flush();}
template<typename T>
ostream& operator<< (T a){writeint(a);return *this;}
ostream& operator<< (const char c){putchar(c);return *this;}
ostream& operator<< (char *s){writestr(s);return *this;}
ostream& operator<< (const char *s){writestr(s);return *this;}
};
istream cin(stdin);
ostream cout(stdout);
const char endl='\n',sep=' ';
}
int main()
{
char s[10];
qio::istream input("1.txt");
qio::ostream output("2.txt");
input>>s;
output<<1234<<qio::endl;
return 0;
}
```
update：C版不定参快读
```cpp
#include<bits/stdc++.h>
namespace fastIO
{
char getch()
{
static const int N=1e6;
static char buf[N+10],*p1=NULL,*p2=NULL;
return (p1==p2)&&(p2=(p1=buf)+fread(buf,1,N,stdin),p1==p2)?EOF:*p1++;
}
void putch(char c)
{
#define flush() fwrite(buf,1,len,stdout),len=0
static const int N=1e6;
static char buf[N+10];
static int len=0;
if(c==EOF)flush();
else buf[len++]=c;
if(len==N)flush();
#undef flush
}
inline long long getint()
{
long long a=0;bool f=false;char ch;
while(ch=getch(),ch<'0'||ch>'9')f=ch=='-';
do a=a*10+ch-'0',ch=getch(); while(ch>='0'&&ch<='9');
return f?-a:a;
}
void qscanf(char *fmt, ...)
{
va_list ap;
va_start(ap,fmt);
for(char *p=fmt;*p;++p)
if(*p=='%')
{
switch(*++p)
{
case 'd':(*(va_arg(ap,int*)))=getint();break;
case 'l':(*(va_arg(ap,long long*)))=getint();break;
case 'c':(*(va_arg(ap,char*)))=getch();break;
default:break;
}
}
va_end(ap);
}
inline void putint(long long a)
{
static char buf[20],len=0;
if(a<0)putch('-'),a=-a;
do buf[len++]=a%10+'0',a/=10; while(a);
while(len)putch(buf[--len]);
}
void qprintf(char *fmt, ...)
{
va_list ap;
char *p;
va_start(ap, fmt);
for(char *p=fmt;*p;++p)
if(*p=='%')
{
switch(*++p)
{
case 'd':putint(va_arg(ap,int));break;
case 'l':putint(va_arg(ap,long long));break;
case 'c':putch(va_arg(ap,int));break;
default:putch(*p);break;
}
}
else putch(*p);
va_end(ap);
}
void qflush(){putch(EOF);}
}
using fastIO::qscanf;
using fastIO::qprintf;
using fastIO::qflush;
int main()
{
int a;long long b;
qscanf("%d%l",&a,&b);
qprintf("%d %l\n",a,b);
qflush();
return 0;
}
```
几种IO速度比较：
数据量：3e7；数据类型：整形；编译环境：不开O2.
input:
```plain
scanf 18.632s
cin开流同步 21.921s
cin关流同步 6.702s
c++11qread 1.256s
qcin 1.450s
普通fread 1.107s
```
output:
```plain
printf 62.680s
cout开流同步 4.911s
cout关流同步 5.956s
c++11qput 1.980s
qcout 2.235s
普通fwrite 1.946s
```