C++ Program for newton forward interpolation formula

//Program for newton forward interpolation formula

#include
#include
#include
#include
#define MAXN 100
#define ORDER 4
void main()
{
float ax[MAXN],ay[MAXN],diff[MAXN+1][ORDER+1];
float nr=1.0,dr=1.0,x,p,h,yp;
int i,n,j,k;
textcolor(GREEN);
clrscr();
cout<<"enter the value of n : ";
cin>>n;
cout<<"\nenter the values in form x,y\n";
for(i=0;i<=n;i++)
cin>>ax[i]>>ay[i];
cout<<"\nenter the value of x for which y is wanted : ";
cin>>x;
h=ax[1]-ax[0];
for(i=0;i<=n-1;i++)
diff[i][1]=ay[i+1]-ay[i];
for(j=2;j<=ORDER;j++)
for(i=0;i<=n;i++)
diff[i][j]=diff[i+1][j-1]-diff[i][j-1];
i=0;
while(!(ax[i]>x))
i++;
i--;
p=(x-ax[i])/h;
yp=ay[i];
for(k=1;k<=ORDER;k++)
{
nr*=p-k+1;
dr*=k;
yp+=(nr/dr)*diff[i][k];
}
cout<<"\n when x = "<<<", y = "<<<<
delay(200);
cout<<"\a\a";
textcolor(YELLOW);
cout<<"\n\n\a";

cout<<"\n\n";


getch();
}

output:
enter the value of n : 4
enter the values in form x,y
80 5026
85 5674
90 6362
95 7088
100 7854
enter the value of x for which y is wanted : 83
when x = 83, y = 5.41e+03