Interpolation using Guass Forward Interpolation Formula

#include<iostream>
#define N 4
using namespace std;
int main()
{
    float ax[10],ay[10],dtab[10][N+1],x,h,p,y;
    float y0,y1,y2,y3,y4;
    int i,j,k,n;
    cout<<"Enter Value of n: ";
    cin>>n;
    for(i=0;i<n;i++)
        for(j=0;j<n;j++)
            dtab[i][j]=0.0;
           
    cout<<"Enter Value for X and Y respectively\n";
    cout<<"X   Y\n";
    for(i=0;i<n;i++)
        cin>>ax[i]>>ay[i];
       
    cout<<"Enter the value of X for which Y is Required: ";
    cin>>x;
    h=ax[1]-ax[0];
   
    for(i=0;i<=n-1;i++)
        dtab[i][1]=ay[i+1]-ay[i];
    for(j=2;j<=N;j++)
    {
        for(i=0;i<n-j;i++)
            dtab[i][j]=dtab[i+1][j-1]-dtab[i][j-1];
    }
    for(i=0;x>ax[i];i++);
        i--;
    p=(x-ax[i])/h;
    y0=ay[i];
    y1=p*dtab[i][1];
    y2=p*(p-1)*dtab[i-1][2]/2;
    y3=(p+1)*p*(p-1)*dtab[i-1][3]/6;
    y4=(p+1)*p*(p-1)*(p-2)*dtab[i-2][4]/24;
    y=y0+y1+y2+y3+y4;
    cout<<"\nFor X="<<x<<" Y="<<y;
    return 0;
}