foo.cpp: In function 'int main()':
foo.cpp:6:5: error: 'ios_base' has not been declared
     ios_base::sync_with_stdio(0);
     ^
foo.cpp:8:5: error: 'cin' was not declared in this scope
     cin>>a>>b>>c>>d;
     ^
foo.cpp:14:35: error: 'abs' was not declared in this scope
         if(abs(a*x*x*x+b*x*x+c*x+d)<0.01)
                                   ^
foo.cpp:16:29: error: 'printf' was not declared in this scope
             printf("%.2f ",x);
                             ^