0_0_19214741_16096.cpp: In function 'int main()': 0_0_19214741_16096.cpp:8:2: error: 'cin' was not declared in this scope cin>>t; ^ 0_0_19214741_16096.cpp:18:27: error: 'printf' was not declared in this scope printf("%.0lf\n",k); //过了 ^