def __init__(self, words_stats): heap = Heap(True) for word in words_stats: node = TreeNode(word) node.setValue(words_stats[word]) heap.insert(node) self.root = HuffmanBinaryTree.buildTree(words_stats, heap)
def buildTree(words_stats, heap):
if heap.size() == 1:
root = TreeNode("Internal")
root.setLeftEdgeVal(1)
node = heap.extract()
root.setLeft(node)
return root
elif heap.size() == 2:
root = TreeNode("Internal")
root.setLeftEdgeVal(1)
root.setRightEdgeVal(0)
node1 = heap.extract()
root.setLeft(node1)
node2 = heap.extract()
root.setRight(node2)
return root
else:
copy_stats = words_stats.copy()
node1 = heap.extract()
node2 = heap.extract()
new_node = TreeNode(node1.getName() + "/" + node2.getName())
new_node.setValue(node1.getValue() + node2.getValue())
del copy_stats[node1.getName()]
del copy_stats[node2.getName()]
copy_stats[node1.getName() + "/" + node2.getName()] = node1.getValue() + node2.getValue()
heap.insert(new_node)
root = HuffmanBinaryTree.buildTree(copy_stats, heap)
new_node.setName("Internal")
new_node.setValue(0.0)
new_node.setLeftEdgeVal(1)
new_node.setRightEdgeVal(0)
new_node.setLeft(node1)
new_node.setRight(node2)
return root
