peterschussheim
3/21/2017 - 10:20 PM

## https://discuss.leetcode.com/topic/16600/tree-deserializer-and-visualizer-for-python/2

``````class TreeNode:
def __init__(self, val, left=None, right=None):
self.val = val
self.left = left
self.right = right
def __repr__(self):
return 'TreeNode({})'.format(self.val)

def deserialize(string):
if string == '{}':
return None
nodes = [None if val == 'null' else TreeNode(int(val))
for val in string.strip('[]{}').split(',')]
kids = nodes[::-1]
root = kids.pop()
for node in nodes:
if node:
if kids: node.left  = kids.pop()
if kids: node.right = kids.pop()
return root

def drawtree(root):
def height(root):
return 1 + max(height(root.left), height(root.right)) if root else -1
def jumpto(x, y):
t.penup()
t.goto(x, y)
t.pendown()
def draw(node, x, y, dx):
if node:
t.goto(x, y)
jumpto(x, y-20)
t.write(node.val, align='center', font=('Arial', 12, 'normal'))
draw(node.left, x-dx, y-60, dx/2)
jumpto(x, y-20)
draw(node.right, x+dx, y-60, dx/2)
import turtle
t = turtle.Turtle()
t.speed(0); turtle.delay(0)
h = height(root)
jumpto(0, 30*h)
draw(root, 0, 30*h, 40*h)
t.hideturtle()
turtle.mainloop()

if __name__ == '__main__':
drawtree(deserialize('[1,2,3,null,null,4,null,null,5]'))
drawtree(deserialize('[2,1,3,0,7,9,1,2,null,1,0,null,null,8,8,null,null,null,null,7]'))``````