/*
	Lagrange's Interpolation
         Made By  Gaurang Sinha
	  gaurang85.tripod.com
*/


#include<stdio.h>
#include<conio.h>
#include<math.h>

int main()
{
int i,j,n;
float x[20],y[20],t,xv,yv;
clrscr();
printf("Enter the no of elements : ");
scanf("%d",&n);
for(i=0;i<n;i++)
{
printf("\nEnter Value X%d Y%d : ",i,i);
scanf("%f%f",&x[i],&y[i]);
}
printf("\nEnter Value to be found : ");
scanf("%f",&xv);
for(i=0;i<n;i++)
{
t=y[i];
	for(j=0;j<n;j++)
	{
		if(i!=j)
		{
		  t=t*((xv-x[j])/(x[i]-x[j]));
		 }
	 }
 yv=yv+t;
 }
 printf("the value is %f",yv);
 getch();
 return 0;
 }