Skip to content

Latest commit

 

History

History
 
 

0814.binary-tree-pruning

Folders and files

NameName
Last commit message
Last commit date

parent directory

..
 
 
 
 
 
 
 
 
 
 
 
 

题目

We are given the head node root of a binary tree, where additionally every node's value is either a 0 or a 1.

Return the same tree where every subtree (of the given tree) not containing a 1 has been removed.

(Recall that the subtree of a node X is X, plus every node that is a descendant of X.)

Example 1:
Input: [1,null,0,0,1]
Output: [1,null,0,null,1]
Explanation:
Only the red nodes satisfy the property "every subtree not containing a 1".
The diagram on the right represents the answer.

1

Example 2:
Input: [1,0,1,0,0,0,1]
Output: [1,null,1,null,1]

2

Example 3:
Input: [1,1,0,1,1,0,1,0]
Output: [1,1,0,1,1,null,1]

3

Note:

  1. The binary tree will have at most 100 nodes.
  2. The value of each node will only be 0 or 1.

解题思路

见程序注释