forked from keon/algorithms
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathlevel_order.py
More file actions
37 lines (34 loc) · 719 Bytes
/
level_order.py
File metadata and controls
37 lines (34 loc) · 719 Bytes
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
"""
Given a binary tree, return the level order traversal of
its nodes' values. (ie, from left to right, level by level).
For example:
Given binary tree [3,9,20,null,null,15,7],
3
/ \
9 20
/ \
15 7
return its level order traversal as:
[
[3],
[9,20],
[15,7]
]
"""
def level_order(root):
ans = []
if not root:
return ans
level = [root]
while level:
current = []
new_level = []
for node in level:
current.append(node.val)
if node.left:
new_level.append(node.left)
if node.right:
new_level.append(node.right)
level = new_level
ans.append(current)
return ans