0_0_29046274_6493.cpp 0_0_29046274_6493.cpp(18) : error C2065: “z”: 未声明的标识符 0_0_29046274_6493.cpp(21) : error C2065: “z”: 未声明的标识符 0_0_29046274_6493.cpp(26) : error C2065: “z”: 未声明的标识符