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0_0_39271475_20771.cpp
0_0_39271475_20771.cpp(5) : error C2365: “y1”: 重定义；以前的定义是“函数”
        VC2013\INCLUDE\math.h(1001) : 参见“y1”的声明
0_0_39271475_20771.cpp(10) : error C2668: “pow”: 对重载函数的调用不明确
        VC2013\INCLUDE\math.h(1233): 可能是“long double pow(long double,int) throw()”
        VC2013\INCLUDE\math.h(1231): 或       “long double pow(long double,long double) throw()”
        VC2013\INCLUDE\math.h(1117): 或       “float pow(float,int) throw()”
        VC2013\INCLUDE\math.h(1115): 或       “float pow(float,float) throw()”
        VC2013\INCLUDE\math.h(1027): 或       “double pow(double,int) throw()”
        VC2013\INCLUDE\math.h(512): 或       “double pow(double,double)”
        尝试匹配参数列表“(int, int)”时
0_0_39271475_20771.cpp(12) : error C2668: “sqrt”: 对重载函数的调用不明确
        VC2013\INCLUDE\math.h(1251): 可能是“long double sqrt(long double) throw()”
        VC2013\INCLUDE\math.h(1135): 或       “float sqrt(float) throw()”
        VC2013\INCLUDE\math.h(521): 或       “double sqrt(double)”
        尝试匹配参数列表“(int)”时
0_0_39271475_20771.cpp(19) : error C2107: 非法索引，不允许间接寻址