求助!!!!!!!!!!各位大虾!
c++中无穷大和pi用什么表示啊?位于哪些头文件啊? 问题点数：20、回复次数：7Top
1 楼pcboyxhy（-273.15℃）回复于 2006-11-03 20:42:34 得分 0
没听说过Top
2 楼weijiangshanwww（天气预报:今天会下分,偶尔下几颗星星!）回复于 2006-11-03 20:47:02 得分 2
pi用什么表示?
===============
PI就是用个变量了,声明为CONST,根据你要的精度,选择是不是长整型,或者LONG LONG DOUBLE..
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3 楼weijiangshanwww（天气预报:今天会下分,偶尔下几颗星星!）回复于 2006-11-03 20:48:25 得分 3
选择是不是长整型
===============
说错了，是选择是不是LONG 型的.
至于无穷大,只要给定一个界限就好了.
我也没见过有无穷大的数Top
4 楼jixingzhong（瞌睡虫·星辰）回复于 2006-11-03 20:48:44 得分 0
limits.hTop
5 楼jixingzhong（瞌睡虫·星辰）回复于 2006-11-03 20:50:23 得分 10
/*
* limits.h
*
* Defines constants for the sizes of integral types.
*
* NOTE: GCC should supply a version of this header and it should be safe to
* use that version instead of this one (maybe safer).
*
* This file is part of the Mingw32 package.
*
* Contributors:
* Created by Colin Peters <colin@bird.fu.is.saga-u.ac.jp>
*
* THIS SOFTWARE IS NOT COPYRIGHTED
*
* This source code is offered for use in the public domain. You may
* use, modify or distribute it freely.
*
* This code is distributed in the hope that it will be useful but
* WITHOUT ANY WARRANTY. ALL WARRANTIES, EXPRESS OR IMPLIED ARE HEREBY
* DISCLAIMED. This includes but is not limited to warranties of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* $Revision: 1.3 $
* $Author: dannysmith $
* $Date: 2001/11/29 04:26:33 $
*
*/
#ifndef _LIMITS_H_
#define _LIMITS_H_
/* All the headers include this file. */
#include <_mingw.h>
/*
* File system limits
*
* TODO: NAME_MAX and OPEN_MAX are file system limits or not? Are they the
* same as FILENAME_MAX and FOPEN_MAX from stdio.h?
* NOTE: Apparently the actual size of PATH_MAX is 260, but a space is
* required for the NUL. TODO: Test?
*/
#define PATH_MAX (259)
/*
* Characteristics of the char data type.
*
* TODO: Is MB_LEN_MAX correct?
*/
#define CHAR_BIT 8
#define MB_LEN_MAX 2
#define SCHAR_MIN (-128)
#define SCHAR_MAX 127
#define UCHAR_MAX 255
/* TODO: Is this safe? I think it might just be testing the preprocessor,
* not the compiler itself... */
#if ('\x80' < 0)
#define CHAR_MIN SCHAR_MIN
#define CHAR_MAX SCHAR_MAX
#else
#define CHAR_MIN 0
#define CHAR_MAX UCHAR_MAX
#endif
/*
* Maximum and minimum values for ints.
*/
#define INT_MAX 2147483647
#define INT_MIN (-INT_MAX-1)
#define UINT_MAX 0xffffffff
/*
* Maximum and minimum values for shorts.
*/
#define SHRT_MAX 32767
#define SHRT_MIN (-SHRT_MAX-1)
#define USHRT_MAX 0xffff
/*
* Maximum and minimum values for longs and unsigned longs.
*
* TODO: This is not correct for Alphas, which have 64 bit longs.
*/
#define LONG_MAX 2147483647L
#define LONG_MIN (-LONG_MAX-1)
#define ULONG_MAX 0xffffffffUL
/*
* The GNU C compiler also allows 'long long int'
*/
#if !defined(__STRICT_ANSI__) && defined(__GNUC__)
#define LONG_LONG_MAX 9223372036854775807LL
#define LONG_LONG_MIN (-LONG_LONG_MAX-1)
#define ULONG_LONG_MAX (2ULL * LONG_LONG_MAX + 1)
/* ISO C9x macro names */
#define LLONG_MAX LONG_LONG_MAX
#define LLONG_MIN LONG_LONG_MIN
#define ULLONG_MAX ULONG_LONG_MAX
#endif /* Not Strict ANSI and GNU C compiler */
#endif /* not _LIMITS_H_ */
该文件定义了各个类型的极限值，
C++ 没有表示 无穷 这样的数据的 ～Top
6 楼blue_zyb（）回复于 2006-11-05 13:34:47 得分 2
IEEE浮点表示法中，指数位全部为1，小数位全部为0表示为无穷。
如果符号位为0，表示正无穷;
如果符号位为1，表示负无穷。
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7 楼zuozhuwu（）回复于 2006-11-05 21:26:28 得分 3
pi 在math.h中有定义
最大值：
#include<limits>
numeric_limits<T>::max();返回的就是最大值，其中T代表类型，int，double都行Top
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