format long
clear;



x = [0.3 0.4 0.5 0.6];
e = [0.5488 0.4493 0.3679 0.3012];

y = e-x;

% n = size(x)(2)-1;
n = size(x,2)-1; % teacher revised
Q = zeros(n+1);
Q(:,1) = x';
z = 0;



for i = 1:n
  for j = 1:i
    Q(i+1,j+1) = ( (z-y(i-j+1))*Q(i+1,j)  - (z-y(i+1))*Q(i,j) ) / ( y(i+1) - y(i+1-j) );
  end
end

Q(n+1,n+1)