892638_0_0_7285.cpp 892638_0_0_7285.cpp(46) : error C2668: “acos” : 对重载函数的调用不明确 VC\include\math.h(586): 可能是“long double acos(long double)” VC\include\math.h(538): 或 “float acos(float)” VC\include\math.h(183): 或 “double acos(double)” 试图匹配参数列表“(int)”时