View Compilation Error

0_0_31358892_272.cpp: In function 'int main()':
0_0_31358892_272.cpp:4:5: error: 'cin' was not declared in this scope
     cin>>T;
     ^
0_0_31358892_272.cpp:9:17: error: 'cout' was not declared in this scope
         if(x<=y)cout<<"0.000000"<<endl;
                 ^
0_0_31358892_272.cpp:9:35: error: 'endl' was not declared in this scope
         if(x<=y)cout<<"0.000000"<<endl;
                                   ^
0_0_31358892_272.cpp:10:39: error: 'log' was not declared in this scope
         else printf("%.6f\n",1+log(x/y));
                                       ^
0_0_31358892_272.cpp:10:40: error: 'printf' was not declared in this scope
         else printf("%.6f\n",1+log(x/y));
                                        ^