Lecture Notes 03 May 2017

def cut_rod (p, n):
  r = []
  s = []

  for i in range (n + 1):
    r.append (0)
    s.append (0)

  for j in range (1, n + 1):
    max_price = -1
    for k in range (1, j + 1):
      new_price = 0 
      if (k < len(p)):
        new_price = p[k] + r[j - k]
      else:
        new_price = r[j - k]
      if (new_price > max_price):
        max_price = new_price
	# remember the best value of the cut
        s[j] = k
      r[j] = max_price
  return r, s

def main():
  # define the price per length of rod
  p = [0, 1, 5, 8, 9, 10, 17, 17, 20]

  # prompt user for length of rod
  n = int (input ("Enter rod length: "))

  # get the optimal price for cutting the rod of length n
  r, s = cut_rod (p, n)

  # print out the result
  for i in range (1, len(r)):
    print (i, r[i], s[i])
  print ()

  # print the optimal price
  print ("Optimal price = ", r[n])

  # print the cuts of the rod
  while (n > 0):
    print (s[n])
    n = n - s[n]

main()