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Binary Tree Zigzag Level Order Traversal
Bookmark
Input
Example 1
Example 2
Four Levels
Single Node
Empty Tree
Custom
tree
=
[3, 9, 20, null, null, 15, 7]
3
9
20
15
7
L0
L1
L2
queue
level
result
level order, alternating direction
3
9
20
15
7
L0
L1
L2
queue
level
result
level order, alternating direction
3
9
20
15
7
L0
L1
L2
queue
3
front
level
result
level 0:
1 node,
left to right
3
9
20
15
7
L0
L1
L2
queue
9
front
level
3
result
enqueue
9
3
9
20
15
7
L0
L1
L2
queue
9
20
front
level
3
result
enqueue
20
3
9
20
15
7
L0
L1
L2
queue
20
front
level
9
result
[3]
append
9
to current_level
3
9
20
15
7
L0
L1
L2
queue
level
9
20
result
[3]
found left child
15
3
9
20
15
7
L0
L1
L2
queue
15
7
front
level
9
20
result
[3]
enqueue
7
3
9
20
15
7
L0
L1
L2
queue
15
7
front
level
20
9
result
[3]
[20, 9]
result +=
[20, 9]
3
9
20
15
7
L0
L1
L2
queue
level
15
7
result
[3]
[20, 9]
append
7
to current_level
3
9
20
15
7
L0
L1
L2
queue
level
result
[3]
[20, 9]
[15, 7]
return [[3], [20, 9], [15, 7]]
algo
master
.
io
Step:
Start: zigzag level order traversal with BFS
0 / 22
Input
Example 1
Example 2
Four Levels
Single Node
Empty Tree
Custom
tree
=
[3, 9, 20, null, null, 15, 7]
0 / 22
algo
master
.
io
Step:
Start: zigzag level order traversal with BFS
