c++中的数值最值

数值最值"/>

c++中的数值最值

在leetcode题155. Min Stack (Easy)时，遇到了需要用到int类型最大值的问题，在此做个笔记。

1. 使用stl库

int最大值: std::numeric_limits<int>::max();

int最小值: std::numeric_limits<int>::min();

double最大值：std::numeric_limits<double>::infinity();

2.包含头文件limits.h

int最大值: INT_MAX

int最小值: INT_MIN

float最大值：FLX_MAX

float最小值：FLX_MIN

long 最大值：LONG_MAX

long 最小值：LONG_MIN

其中：

• INT_MAX = 2147483647
• INT_MIN = -2147483648

/* Copyright (C) 1992-2018 Free Software Foundation, Inc.This file is part of GCC.GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
</>.  *//* This administrivia gets added to the beginning of limits.hif the system has its own version of limits.h.  *//* We use _GCC_LIMITS_H_ because we want this not to matchany macros that the system's limits.h uses for its own purposes.  */
#ifndef _GCC_LIMITS_H_  /* Terminated in limity.h.  */
#define _GCC_LIMITS_H_#ifndef _LIBC_LIMITS_H_
/* Use "..." so that we find syslimits.h only in this same directory.  */
#include "syslimits.h"
#endif
/* Copyright (C) 1991-2018 Free Software Foundation, Inc.This file is part of GCC.GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
</>.  */#ifndef _LIMITS_H___
#define _LIMITS_H___/* Number of bits in a `char'.  */
#undef CHAR_BIT
#define CHAR_BIT __CHAR_BIT__/* Maximum length of a multibyte character.  */
#ifndef MB_LEN_MAX
#define MB_LEN_MAX 1
#endif/* Minimum and maximum values a `signed char' can hold.  */
#undef SCHAR_MIN
#define SCHAR_MIN (-SCHAR_MAX - 1)
#undef SCHAR_MAX
#define SCHAR_MAX __SCHAR_MAX__/* Maximum value an `unsigned char' can hold.  (Minimum is 0).  */
#undef UCHAR_MAX
#if __SCHAR_MAX__ == __INT_MAX__
# define UCHAR_MAX (SCHAR_MAX * 2U + 1U)
#else
# define UCHAR_MAX (SCHAR_MAX * 2 + 1)
#endif/* Minimum and maximum values a `char' can hold.  */
#ifdef __CHAR_UNSIGNED__
# undef CHAR_MIN
# if __SCHAR_MAX__ == __INT_MAX__
#  define CHAR_MIN 0U
# else
#  define CHAR_MIN 0
# endif
# undef CHAR_MAX
# define CHAR_MAX UCHAR_MAX
#else
# undef CHAR_MIN
# define CHAR_MIN SCHAR_MIN
# undef CHAR_MAX
# define CHAR_MAX SCHAR_MAX
#endif/* Minimum and maximum values a `signed short int' can hold.  */
#undef SHRT_MIN
#define SHRT_MIN (-SHRT_MAX - 1)
#undef SHRT_MAX
#define SHRT_MAX __SHRT_MAX__/* Maximum value an `unsigned short int' can hold.  (Minimum is 0).  */
#undef USHRT_MAX
#if __SHRT_MAX__ == __INT_MAX__
# define USHRT_MAX (SHRT_MAX * 2U + 1U)
#else
# define USHRT_MAX (SHRT_MAX * 2 + 1)
#endif/* Minimum and maximum values a `signed int' can hold.  */
#undef INT_MIN
#define INT_MIN (-INT_MAX - 1)
#undef INT_MAX
#define INT_MAX __INT_MAX__/* Maximum value an `unsigned int' can hold.  (Minimum is 0).  */
#undef UINT_MAX
#define UINT_MAX (INT_MAX * 2U + 1U)/* Minimum and maximum values a `signed long int' can hold.(Same as `int').  */
#undef LONG_MIN
#define LONG_MIN (-LONG_MAX - 1L)
#undef LONG_MAX
#define LONG_MAX __LONG_MAX__/* Maximum value an `unsigned long int' can hold.  (Minimum is 0).  */
#undef ULONG_MAX
#define ULONG_MAX (LONG_MAX * 2UL + 1UL)#if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
/* Minimum and maximum values a `signed long long int' can hold.  */
# undef LLONG_MIN
# define LLONG_MIN (-LLONG_MAX - 1LL)
# undef LLONG_MAX
# define LLONG_MAX __LONG_LONG_MAX__/* Maximum value an `unsigned long long int' can hold.  (Minimum is 0).  */
# undef ULLONG_MAX
# define ULLONG_MAX (LLONG_MAX * 2ULL + 1ULL)
#endif#if defined (__GNU_LIBRARY__) ? defined (__USE_GNU) : !defined (__STRICT_ANSI__)
/* Minimum and maximum values a `signed long long int' can hold.  */
# undef LONG_LONG_MIN
# define LONG_LONG_MIN (-LONG_LONG_MAX - 1LL)
# undef LONG_LONG_MAX
# define LONG_LONG_MAX __LONG_LONG_MAX__/* Maximum value an `unsigned long long int' can hold.  (Minimum is 0).  */
# undef ULONG_LONG_MAX
# define ULONG_LONG_MAX (LONG_LONG_MAX * 2ULL + 1ULL)
#endif#ifdef __STDC_WANT_IEC_60559_BFP_EXT__
/* TS 18661-1 widths of integer types.  */
# undef CHAR_WIDTH
# define CHAR_WIDTH __SCHAR_WIDTH__
# undef SCHAR_WIDTH
# define SCHAR_WIDTH __SCHAR_WIDTH__
# undef UCHAR_WIDTH
# define UCHAR_WIDTH __SCHAR_WIDTH__
# undef SHRT_WIDTH
# define SHRT_WIDTH __SHRT_WIDTH__
# undef USHRT_WIDTH
# define USHRT_WIDTH __SHRT_WIDTH__
# undef INT_WIDTH
# define INT_WIDTH __INT_WIDTH__
# undef UINT_WIDTH
# define UINT_WIDTH __INT_WIDTH__
# undef LONG_WIDTH
# define LONG_WIDTH __LONG_WIDTH__
# undef ULONG_WIDTH
# define ULONG_WIDTH __LONG_WIDTH__
# undef LLONG_WIDTH
# define LLONG_WIDTH __LONG_LONG_WIDTH__
# undef ULLONG_WIDTH
# define ULLONG_WIDTH __LONG_LONG_WIDTH__
#endif#endif /* _LIMITS_H___ */
/* This administrivia gets added to the end of limits.hif the system has its own version of limits.h.  */#else /* not _GCC_LIMITS_H_ */#ifdef _GCC_NEXT_LIMITS_H
#include_next <limits.h>		/* recurse down to the real one */
#endif#endif /* not _GCC_LIMITS_H_ */