0_0_31999033_20494.cpp 0_0_31999033_20494.cpp(1) : error C2065: “cin”: 未声明的标识符 0_0_31999033_20494.cpp(1) : error C3861: “scanf”: 找不到标识符 0_0_31999033_20494.cpp(1) : error C3861: “printf”: 找不到标识符