from TreeNode import *

# takes as input name of text file, fname, and returns
# a list of pairs (c,n), where c is a character in the file
# and n is the number of times c appears in the file
def freq(fname):
	pass

# takes a list of character frequencies (c,n) sorted in increasing order
# of frequency and returns a list of initial tree objects
def construct_initial_trees(sorted_frequencies):
	pass

# takes as input two Huffman trees and returns a single tree
# with a root and the two trees as sub-trees
def combine(t1,t2):
	pass

# takes as input a new tree t and a list of sorted trees and
# returns a sorted list of trees after inserting t into tlist.
def insertHT(t,tlist):
	pass

# takes as input a list of sorted trees, tlist, and returns a Huffman tree
# generated from tlist
def construct_huffman_tree(tlist):
	pass

# takes as input a character c and the Huffman tree, htree, and
# returns the Huffman code for c based on htree
def code(c,htree):
	pass

# takes as input a plain text string s, and the Huffman tree, htree,
# and returns the Huffman code for s
def huffman_encoding(s,htree):
	pass

# takes as input a string s and the Huffman tree, htree, and
# returns the plain text for s based on htree
def huffman_decoding(s,htree):
	pass

def pretty_print(htree,indent):
  if htree != None:
    spaces = ""
    for x in range(indent):
      spaces = " "+spaces
    print(spaces,htree._symbols,htree._weight)
    pretty_print(htree._left,indent+2)
    pretty_print(htree._right,indent+2)