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0_0_20991529_13905.cpp
0_0_20991529_13905.cpp(41) : error C2065: “s”: 未声明的标识符
0_0_20991529_13905.cpp(41) : error C2228: “.pop”的左边必须有类/结构/联合
        类型是“unknown-type”
0_0_20991529_13905.cpp(47) : error C2065: “s”: 未声明的标识符
0_0_20991529_13905.cpp(47) : error C2228: “.push”的左边必须有类/结构/联合
        类型是“unknown-type”