0_0_19149427_21349.cpp 0_0_19149427_21349.cpp(7) : error C2065: “n”: 未声明的标识符 0_0_19149427_21349.cpp(8) : error C2065: “n”: 未声明的标识符 0_0_19149427_21349.cpp(12) : error C2065: “N”: 未声明的标识符