Numerical Analysis/Neville's algorithm code

The basic outline of a Matlab program that evaluates an interpolating polynomial using Neville's Algorithm given inputs of a point at which to evaluate (x0), a matrix of the x terms of the ordered pairs (x), and a matrix of the y terms of the ordered pairs (y) is given below. The numbers in the parenthese at the end of the comments correspond to questions given below the code.

Questions
(1) Is the degree of the polynomial equal to the length of x minus 1 or the length of x plus one? Solution: length of x minus 1

(2) How many rows and columns should matrix p have? Solution: n+1 rows and n+1 columns

(3) When should the loop end? Solution: when i is equal to the length of x, which is also when i is equal to n+1

(4) When should the loop end? Solution: when j is equal to n+1

(5) When should the loop end? Solution: when i is equal to n+1-j

(6) What term of the matrix is the output value? Solution: p = p(1,n+1)