Main.cc:3:6: error: expected constructor, destructor, or type conversion before ‘(’ token scanf("%f%f%f%f",&x1,&y1,&x2,&y2); ^ Main.cc:4:1: error: ‘z’ does not name a type z=sqrt(pow(x1-x2,2)+pow(y1-y2,2)); ^ Main.cc:5:1: error: ‘cout’ does not name a type cout<