0_0_27421509_30165.cpp 0_0_27421509_30165.cpp(18) : error C3861: “scanf”: 找不到标识符 0_0_27421509_30165.cpp(20) : error C3861: “printf”: 找不到标识符 0_0_27421509_30165.cpp(23) : error C3861: “printf”: 找不到标识符