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Binary Tree Level Order Traversal
Bookmark
Input
Example 1
Complete Tree
Four Levels
Custom
tree
=
[3, 9, 20, null, null, 15, 7]
3
9
20
15
7
L0
L1
L2
queue
level
result
level-order traversal (BFS)
3
9
20
15
7
L0
L1
L2
queue
level
result
level-order traversal (BFS)
3
9
20
15
7
L0
L1
L2
queue
3
front
level
result
level 0:
1 node,
current_level = []
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
9
20
front
level
result
[3]
level 1:
2 nodes,
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
front
level
9
20
result
[3]
found right child
7
3
9
20
15
7
L0
L1
L2
queue
15
7
front
level
9
20
result
[3]
[9, 20]
result +=
[9, 20]
3
9
20
15
7
L0
L1
L2
queue
level
15
7
result
[3]
[9, 20]
append
7
to current_level
3
9
20
15
7
L0
L1
L2
queue
level
result
[3]
[9, 20]
[15, 7]
return [[3], [9, 20], [15, 7]]
algo
master
.
io
Step:
Start: traverse the tree level by level with BFS
0 / 21
Input
Example 1
Complete Tree
Four Levels
Custom
tree
=
[3, 9, 20, null, null, 15, 7]
0 / 21
algo
master
.
io
Step:
Start: traverse the tree level by level with BFS
