#include<assert.h>
#include<stdio.h>
**#include<stdlib.h>**
#include<string.h>
**#include<stdlib.h>**
#include<time.h>
stdlib.h is included for two times, but why?
stdlib。h包含2次，为什么?
1 个解决方案
#1
3
There is exactly one non-idempotent standard header in the C standard: <assert.h>.
C++ inherits that and adds its own adaptation: <cassert>.
在C标准中，只有一个非幂等标准的标头:
Even for those, multiple inclusion has no effect without changing NDEBUG between them.
即使是这样，在不改变它们之间的NDEBUG的情况下，多重包容也没有效果。
Your own headers, as well as headers from other libraries you might use, should use include guards (or the unportable but often working #pragma once).
您自己的头部，以及您可能使用的其他库的头，应该使用包括警卫(或者是不可移植的，但通常是工作#pragma一次)。
If you sort your headers (include the implementation-files own header first though), you can easily eliminate duplicates and don't need to rely on that.
如果您对您的头文件进行排序(首先包括实现文件自己的头文件)，您可以很容易地消除重复，并且不需要依赖它。
#1
3
There is exactly one non-idempotent standard header in the C standard: <assert.h>.
C++ inherits that and adds its own adaptation: <cassert>.
在C标准中，只有一个非幂等标准的标头:
Even for those, multiple inclusion has no effect without changing NDEBUG between them.
即使是这样，在不改变它们之间的NDEBUG的情况下，多重包容也没有效果。
Your own headers, as well as headers from other libraries you might use, should use include guards (or the unportable but often working #pragma once).
您自己的头部，以及您可能使用的其他库的头，应该使用包括警卫(或者是不可移植的，但通常是工作#pragma一次)。
If you sort your headers (include the implementation-files own header first though), you can easily eliminate duplicates and don't need to rely on that.
如果您对您的头文件进行排序(首先包括实现文件自己的头文件)，您可以很容易地消除重复，并且不需要依赖它。