C++ program error
<p>I am not able to solve 3 error . Programs implementation is right but not sure how to get rid of 3 errors</p>

<pre><code># include &lt;iostream.h&gt;
# include &lt; conio.h&gt;
void main() {
    class coord {
        float x;
        float y;
        //Constructor
        coord(float init_x,float init_y) {
            x= init_x;
            y= init_y;
        }
        void set(float f1, float f2) {
            x = f1;
            y = f2;
        }
        float get_x() {return x;}
        float get_y() {return y;}
        virtual void plot() {
            cout&lt;&lt;x;
            cout&lt;&lt;y;
        };
        class 3d_coord: public coord {
            float z;
            //constructor
            3d_coord(float init_x,float init_y,float init_z): coord(init_x,init_y) {
                z= init_z;
            }
            void set(float f1,float f2,float f3) {
                coord::set(f1, f2); z = f3;
            }
            float get_z() {  return z; }

            virtual void plot() { 
                coord::plot();
                cout&lt;&lt;z;
            };

            int test
            void *ptr;

            cin&gt;&gt;test;
            coord a(1.1, 2.2);
            3d_coord b(3.0, 4.0, 5.0);
            if (test)
                ptr = &amp;a;
            else
                    ptr = &amp;b;
            ptr-&gt; plot();
        }
    }
</code></pre>
