Help me with solving

[Basota1992]

#include <iostream>
using namespace std;
#include <conio.h>
#include <math.h>

class point {public:double ab,or;
public:point() {};
point (double a, double b) {ab=a; or=b;}
point (const point& w){ab=w.ab;or=w.or; }
double dp (point &q);
};
double point::dp(point &q)
{ return sqrt((ab-q.ab)*(ab-q.ab)+(or-q.or)*(or-q.or));
};

class Poligon:public point
{ int n;
point *p;
public: Poligon();
void afisv();
double aria();
};

Poligon::Poligon()
{cout<<"Introduceti numarul de virfuri a poligonului convex, in ordinea stricta ";cin>>n;
p=new point[n];
for(int i=0;i<n;i++){double a,b;
cout<<"Introduceti abcisa virfului poligonuli x=";cin>>a;
cout<<"Introduceti ordonata virfului poligonuli y=";cin>>b;
p[i]=point(a,b);};
;};

double Poligon::aria(){
double *a=new double[n-1];a[n-2]=0;
for (int i=1;i<=n-2;i++) {double s;s=(p[0].dp(p[i])+p[0].dp(p[i+1])+p[i].dp(p[i+1]))/2;a[i-1]=sqrt(s*(s-p[0].dp(p[i]))*(s-p[0].dp(p[i+1]))*(s-p[i].dp(p[i+1])));}
for (int i=0;i<n-2;i++) a[n-2]+=a[i];
return a[n-2];
};

[Peter87]

What is the problem?

[Moschops]

Do you have a question?

[Basota1992]

It doesn't work.

[Athar]

That's neither a question nor a problem description.

[bluecoder]

Please specify what does not work ? what does the program suppose to do ?