在Python中将二叉树插入矩阵

Question

Lets say I have the following binary tree:

..............6
............/....\
...........9......4
........../..\......\
.........5....1.....3
..........\........./
...........0.......7

I would like to print it from the very left to the right:

5 9 0 6 1 4 7 3

I would like to enter it to a matrix in BF way. So I'll be able to transform the matrix. How can I do it? Here is the code for initiating the binary tree:

class Node:
    def __init__(self,val):
        self.val = val
        self.left = None
        self.right = None



root =  Node(1)
root.left = Node(2)
root.right = Node(3)
root.left.left = Node(4)
root.left.right = Node(5)
root.right.left = Node(6)
root.right.right = Node(7)
root.right.left.right = Node(8)
root.right.right.right = Node(9)

The required matrix:

0 0 0 6 0 0 0 0
0 0 0 9 4 0 0 0
0 0 5 1 0 3 0 0
0 0 0 0 0 0 7 0

Answer 1

Happy to help :)

res = []
def findMinMax(node, minimum, maximum, hd): 
    if node is None: 
        return 
    if hd < minimum[0] : 
        minimum[0] = hd 
    elif hd > maximum[0]: 
        maximum[0] = hd 

    findMinMax(node.left, minimum, maximum, hd-1) 
    findMinMax(node.right, minimum, maximum, hd+1) 

def printVerticalLine(node, line_no, hd, ls): 
    if node is None: 
        return
    if hd == line_no: 
        ls.append(node.data) 
    printVerticalLine(node.left, line_no, hd-1,ls) 
    printVerticalLine(node.right, line_no, hd+1,ls) 

def verticalOrder(root):
    minimum = [0] 
    maximum = [0] 
    findMinMax(root, minimum, maximum, 0)  
    for line_no in range(minimum[0], maximum[0]+1): 
        r = []
        printVerticalLine(root, line_no, 0,r)
        res.append(r)
    print(res)