(12) : error C2668: “pow”: 对重载函数的调用不明确
        VC8\include\math.h(575): 可能是“long double pow(long double,int)”
        VC8\include\math.h(573): 或“long double pow(long double,long double)”
        VC8\include\math.h(527): 或“float pow(float,int)”
        VC8\include\math.h(525): 或“float pow(float,float)”
        VC8\include\math.h(489): 或“double pow(double,int)”
        VC8\include\math.h(123): 或“double pow(double,double)”
        试图匹配参数列表“(int, size_t)”时