Function in Matlab - Programming

Write a function in Matlab that takes as input a size n and a tridiagonal matrix given as three vectors: n by 1 vector v representing the main diagonal, (n-1) by 1 vector w representing the upper diagonal, and (n-1) by 1 vector z representing the lower diagonal. Have this function output the LU factorization with the U as two vectors and the L as one vector representing the diagonals. Also output the number of flops used. Use only basic programming. 
  

(a) Write out or print out your function. 
  (b) Run the case with n = 10, v the vector of 2's, w and z the vector of -1's, and b the vector of 1's. Write down your results for the diagonals of L and U. 
  (c) Run the case with n = 50 and n = 100 with v the vector of 2's, w and z the vector of -1's. Write down your results for the number of flops used.