TheAlgorithms-C/computer-oriented-statistical-methods/lagrange_theorem.C

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
#include<math.h>
void main()
{
	float x[20],y[20],a,sum,p;
	int n,i,j;
	clrscr();
	printf("Enter the no of entry to insert->");
	scanf("%d",&n);

	for(i=0;i<n;i++)
	{
		printf("enter the value of x%d->",i);
		scanf("%f",&x[i]);
		printf("enter the value of y%d->",i);
		scanf("%f",&y[i]);
	}
	printf("\n X \t\t Y \n");
		printf("----------------------------\n");
		for(i=0;i<n;i++)
		{
			printf("%f\t",x[i]);
			printf("%f\n",y[i]);
		}
		printf("\nenter the value of x for interpolation:");
		scanf("%f",&a)
		sum=0;
		for(i=0;i<n;i++)
		{
			p=1.0;
			for(j=0;j<n;j++)
			{

			if(i !=j)
			{
				p=p*(a-x[j])/(x[i]-x[j]);
			}
			sum=sum+y[i]*p;
		}
		printf("ans is->%f",sum);
		getch();

}}