Code Snippets for IO Bursting in OJ

fastio.hpp

/* 
 * OJ中加速IO常用的代码片段
 * Author Jacob C
 * THU_ID 2014010812
 */

//OJ中常用的头文件和预编译指令
#ifndef _OJ_
#define DEBUG
#endif

#ifdef __cplusplus

#include <cstdio>
#include <cstdlib>
#ifdef DEBUG
#include <iostream>
using namespace std;
#endif

#else

#include <stdio.h>
#include <stdlib.h>
#define true 1
#define false 0
typedef char bool;
#define newchar(n) (char*)malloc((n)*sizeof(char))
#define newbool(n) (char*)malloc((n)*sizeof(char))
#define newint(n) (int*)malloc((n)*sizeof(int))
#define newuint(n) (unsigned int*)malloc((n)*sizeof(unsigned int*))

#endif

typedef unsigned int uint;
typedef long long int llint;
typedef unsigned long long int ullint;


//缓冲区大小设置 
#ifndef BUFFER_SIZE
#warning "buffer size is set to 1<<20, max size that doesn't cause stack overflow is 26"
#define BUFFER_SIZE 20
#endif

//定义BURST_IO为使用自定义类fastio加速（使用fread），不定义BURST_IO则为setvbuf方式的自定义类加速
#ifdef BURST_IO
/***** fread版本 *****/

#ifdef __cplusplus
//C++版本 fread 从http://www.cnblogs.com/jklongint/p/4774075.html更改而来
class fastio
{
public:
	fastio()
	{
		in = new char[insize];
		out = new char[outsize];
		pin = in;
		countin = countout = 0;
		sin = stdin;
		sout = stdout;
		read2mem();
	}
	fastio(FILE *fin, FILE *fout)
	{
		in = new char[insize];
		out = new char[outsize];
		pin = in;
		countin = countout = 0;
		sin = fin;
		sout = fout;
	}
	~fastio()
	{
		write2disk();
	}
	int read2mem()
	{
		return countin = fread(in, 1, insize, sin);
		fclose(sin);
	}
	int write2disk()
	{
		return fwrite(out, 1, countout, sout);
		fclose(sout);
	}
	int read() { return 0; }
	template<typename T, typename ...R> int read(T &f, R &...r)
	{
		if (get(f) == -1) return -1;
		c = read(r...);
		if (c == -1) return -1;
		return 1 + c;
	}
	void write()
	{
		put('\n');
	}
	template<typename T, typename ...R> void write(const T x, const R ...r)
	{
		put(x);
		write(r...);
	}
private:
	const static int insize = (1 << BUFFER_SIZE), outsize = (1 << BUFFER_SIZE); //放在堆上最大为18
	char *in, *out, *pin; //使用如char in[insize]这样的静态声明可能会导致爆栈
	FILE *sin, *sout;
	int countin, countout, a[20], c, negative;

	/*** read的实现 ***/
	inline bool digit(const char ch)
	{
		return ch == '-' || ch >= '0' && ch <= '9';
	}
	int get(char s[])
	{
		while ((*pin == ' ' || *pin == '\n') && pin - in != countin) pin++;
		if (pin - in == countin) return -1;
		while (*pin != ' ' && *pin != '\n' && pin - in != countin) *s++ = *pin++;
		*s = 0;
		return 1;
	}
	int get(char &ch)
	{
		if (pin - in == countin) return -1;
		ch = *pin++;
		return 1;
	}
	int get(int &buf)
	{
		while (!digit(*pin) && pin - in != countin) pin++;
		if (pin - in == countin) return -1;
		buf = 0;
		negative = 0;
		if (*pin == '-')
		{
			negative = 1;
			pin++;
		}
		while (digit(*pin) && pin - in != countin)
		{
			buf = buf * 10 + *pin - '0';
			pin++;
		}
		if (negative) buf = -buf;
		return 1;
	}
	int get(uint &buf)
	{
		while (!digit(*pin) && pin - in != countin) pin++;
		if (pin - in == countin) return -1;
		buf = 0;
		while (digit(*pin) && pin - in != countin)
		{
			buf = buf * 10 + *pin - '0';
			pin++;
		}
		return 1;
	}
	/*** write的实现 ***/
	void put(uint x)
	{
		c = 0;
		a[c++] = x % 10 + '0';
		x /= 10;
		while (x)
		{
			a[c++] = x % 10 + '0';
			x /= 10;
		}
		while (c)
		{
			out[countout++] = a[--c];
		}
	}
	void put(int x)
	{
		c = 0;
		negative = x < 0;
		if (negative)
		{
			x = -x;
			out[countout++] = '-';
		}
		a[c++] = x % 10 + '0';
		x /= 10;
		while (x)
		{
			a[c++] = x % 10 + '0';
			x /= 10;
		}
		while (c)
		{
			out[countout++] = a[--c];
		}
	}
	void put(const char &ch)
	{
		out[countout++] = ch;
	}
	void put(char s[])
	{
		while (*s) out[countout++] = *s++;
	}
	void put(const char s[])
	{
		while (*s) out[countout++] = *s++;
	}
};
#else
//C语言版本 fread
#warning "C version fastio has not implemented output, use printf instead." 
typedef struct iobuf_t {
	char* inbuf;
	char* countin;
	char* pin;
	char* outbuf;
	int countout;
}fastio;
	
fastio* initio()
{
	const int SZ = 1 << BUFFER_SIZE;  //IO buff的大小  
	fastio* buf = (fastio*)malloc(sizeof(fastio));
	buf->inbuf = newchar(SZ);
	buf->outbuf = newchar(SZ);
	buf->countin = fread(buf->inbuf, 1, SZ, stdin) + buf->inbuf;
	buf->pin = buf->inbuf;
	buf->countout=0;
	return buf;
}
void finishio(fastio *buf)
{
	return fwrite(buf->outbuf, 1, buf->countout, stdout);
	fclose(stdout);
}
bool digit(const char ch)
{
	return ch == '-' || ch >= '0' && ch <= '9';
}
uint getu(fastio *buf)
{
	uint val = 0;
	while (!digit(*(buf->pin)) && buf->pin != buf->countin) buf->pin++;
	while (digit(*(buf->pin)) && buf->pin != buf->countin)
	{
		val = val * 10 + *(buf->pin) - '0';
		buf->pin++;
	}
	return val;
}
void putu(fastio *buf, uint x)
{
	char a[20];
	int c = 0;
	a[c++] = x % 10 + '0';
	x /= 10;
	while (x)
	{
		a[c++] = x % 10 + '0';
		x /= 10;
	}
	while (c)
	{
		buf->outbuf[buf->countout++] = a[--c];
	}
	buf->outbuf[buf->countout++] = '\t';
}
#endif

#else
/***** setvbuf版本 *****/

#ifdef __cplusplus
//C++版本 setvbuf
const int SZ = 1 << BUFFER_SIZE;  //提升IO buff   
struct fastio {  
    char inbuf[SZ];  
    char outbuf[SZ];  
    fastio()
	{  
        setvbuf(stdin, inbuf, _IOFBF, SZ);  
        setvbuf(stdout, outbuf, _IOFBF, SZ);  
    }  
}io;
#else
//C语言版本 setvbuf
void burstio()
{
	const int SZ = 1 << BUFFER_SIZE;  //提升IO buff  
	char *inbuf = (char*)malloc(SZ * sizeof(char));
	char *outbuf = (char*)malloc(SZ * sizeof(char));
	setvbuf(stdin, inbuf, _IOFBF, SZ);
	setvbuf(stdout, outbuf, _IOFBF, SZ);
}
#endif

#endif

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