//埃特金插值算法源程序:
#include<iostream.h>
#define SIZE 10
int main()
{
	int n,i=1,j=1;
	double xx;
	double x[SIZE];
	double y[SIZE];
	cout<<"**********埃特金插值***********"<<endl<<endl;
	cout<<"輸入已知插值結點數目:   ";
	cin>>n;
	cout<<"依次輸入結點的坐標:   x y"<<endl;
	while(i<=n)
	{
		cout<<"第 "<<i<<"個點的坐標為  ";
		cin>>x[i]>>y[i];
		i++;
	}
	cout<<"輸入所求插值結點x坐標:   ";
	cin>>xx;
	for(i=1;i<=n;i++)
	{
		for(j=i+1;j<=n;j++)
			y[j]=(xx-x[i])*y[j]/(x[j]-x[i])+(xx-x[j])*y[i]/(x[i]-x[j]);
	}
	cout<<"所求y坐標為:  "<<y[n]<<endl; }