程序代码：

/* Function prototypes */

#ifndef _CRT_ALGO_DEFINED
#define _CRT_ALGO_DEFINED
#if __STDC_WANT_SECURE_LIB__
_Check_return_ _CRTIMP void * __cdecl bsearch_s(_In_ const void * _Key, _In_bytecount_x_(_NumOfElements * _SizeOfElements) const void * _Base, 
        _In_ rsize_t _NumOfElements, _In_ rsize_t _SizeOfElements,
        _In_ int (__cdecl * _PtFuncCompare)(void *, const void *, const void *), void * _Context);
#endif
_Check_return_ _CRTIMP void * __cdecl bsearch(_In_ const void * _Key, _In_bytecount_x_(_NumOfElements * _SizeOfElements) const void * _Base, 
        _In_ size_t _NumOfElements, _In_ size_t _SizeOfElements,
        _In_ int (__cdecl * _PtFuncCompare)(const void *, const void *));

#if __STDC_WANT_SECURE_LIB__
_CRTIMP void __cdecl qsort_s(_Inout_bytecap_x_(_NumOfElements* _SizeOfElements) void * _Base, 
        _In_ rsize_t _NumOfElements, _In_ rsize_t _SizeOfElements,
        _In_ int (__cdecl * _PtFuncCompare)(void *, const void *, const void *), void *_Context);
#endif
_CRTIMP void __cdecl qsort(_Inout_bytecap_x_(_NumOfElements * _SizeOfElements) void * _Base, 
    _In_ size_t _NumOfElements, _In_ size_t _SizeOfElements, 
        _In_ int (__cdecl * _PtFuncCompare)(const void *, const void *));
#endif

程序代码：

#ifdef _CRT_ALGO_DEFINED
    qsort(...);
#else
    MyOwnQsort(...);
#endif