Lagrange Interpolation

Write a program in C to find the value of 𝒚 for 𝒙 = 𝟑 given the data using Lagrange’s Interpolation:
x: 1, 2, 4
y: 1, 4, 16

#include <stdio.h>
#include <conio.h>
int main(){
 clrscr();
 double x[3]={1,2,4}, y[3]={1,4,16}, xp=3, yp=0, L;
 for(int i=0;i<3;i++){
 L=1;
 for(int j=0;j<3;j++)
 if(j!=i) L *= (xp - x[j])/(x[i] - x[j]);
 yp += L * y[i];
 }
 printf("\n\nFor x=%.1f, y=%.2f\n", xp, yp);
 getch();
 return 0;
}

Output