Newton’s Divided Difference Method

Write a program in C to find 𝒚 at 𝒙 = 𝟑 using Newton’s Divided Difference Method given data:
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}, p[3][3], xp = 3, yp;
 int i, j; // Declare loop variables here (outside loops)
 for (i = 0; i < 3; i++)
 p[i][0] = y[i];
 for (j = 1; j < 3; j++)
 for (i = 0; i < 3 - j; i++)
p[
i][j] = (p[i + 1][j - 1] - p[i][j - 1]) / (x[i + j] - x[i]);
 yp = p[0][0] + (xp - x[0]) * p[0][1] + (xp - x[0]) * (xp - x[1]) * p[0][2];
 printf("\n\n\ty(%.1f) = %.2f\n", xp, yp);
 getch();
 return 0;
}

Output