#include <iostream.h>
#include <math.h>
void main()

{
	
	double x[6]={0,1,3,4,7,9};
	double f[6];
	double first[5], second[4], third[3], fourth[2];
	int i;
	for(i=0;i<6;i++)f[i]=pow(x[i],3); // function
	for(i=0;i<5;i++)first[i]=(f[i]-f[i+1])/(x[i]-x[i+1]);// first divided difference
	for(i=0;i<4;i++)second[i]=(first[i]-first[i+1])/(x[i]-x[i+2]);// second divided difference
	for(i=0;i<3;i++)third[i]=(second[i]-second[i+1])/(x[i]-x[i+3]);// third divided difference
	for(i=0;i<2;i++)fourth[i]=(third[i]-third[i+1])/(x[i]-x[i+4]);// fourth divided difference
	for(i=0;i<6;i++)cout<<f[i]<<"\t";cout<<endl;
	for(i=0;i<5;i++)cout<<first[i]<<"\t";cout<<endl;
	for(i=0;i<4;i++)cout<<second[i]<<"\t";cout<<endl;
	for(i=0;i<3;i++)cout<<third[i]<<"\t";cout<<endl;
	for(i=0;i<2;i++)cout<<fourth[i]<<"\t";cout<<endl;
}