Question list
- How do we transfer an array to a binary tree?
we fill withNullif we do not need it when it is necessary.
graph TB
A((12))
B((4))
C((15))
D((Null))
E((6))
F((10))
G((Null))
A-->B
A-->C
B-->D
B-->E
C-->F
C-->G
The array to describe the binary tree above is [12, 4, 15, Null, 6, 10, Null] and the last Null can be deleted as it is not necessary.