分析：在Visual Studio上使用math.h库时与其他库数学库冲突，我们可以通过添加宏定义“_USE_MATH_DEFINES”来消除math.h定义的宏。
#if defined _USE_MATH_DEFINES && !defined _MATH_DEFINES_DEFINED #define _MATH_DEFINES_DEFINED // Definitions of useful mathematical constants // // Define _USE_MATH_DEFINES before including <math.h> to expose these macro // definitions for common math constants. These are placed under an #ifdef // since these commonly-defined names are not part of the C or C++ standards #define M_E 2.71828182845904523536 // e #define M_LOG2E 1.44269504088896340736 // log2(e) #define M_LOG10E 0.434294481903251827651 // log10(e) #define M_LN2 0.693147180559945309417 // ln(2) #define M_LN10 2.30258509299404568402 // ln(10) #define M_PI 3.14159265358979323846 // pi #define M_PI_2 1.57079632679489661923 // pi/2 #define M_PI_4 0.785398163397448309616 // pi/4 #define M_1_PI 0.318309886183790671538 // 1/pi #define M_2_PI 0.636619772367581343076 // 2/pi #define M_2_SQRTPI 1.12837916709551257390 // 2/sqrt(pi) #define M_SQRT2 1.41421356237309504880 // sqrt(2) #define M_SQRT1_2 0.707106781186547524401 // 1/sqrt(2) #endif