golang 解法, 执行用时: 0 ms, 内存消耗: 2.2 MB, 提交时间: 2022-11-23 15:46:18

/**
 * Definition for a binary tree node.
 * type TreeNode struct {
 *     Val int
 *     Left *TreeNode
 *     Right *TreeNode
 * }
 */
func pruneTree(root *TreeNode) *TreeNode {
    if root == nil {
        return nil
    }
    if root.Left != nil {
        root.Left = pruneTree(root.Left)
    }
    if root.Right != nil {
        root.Right = pruneTree(root.Right)
    }
    
    if root.Left == nil && root.Right == nil && root.Val == 0 {
        return nil
    }
    return root
}

python3 解法, 执行用时: 44 ms, 内存消耗: 14.9 MB, 提交时间: 2022-11-23 11:53:30

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def pruneTree(self, root: TreeNode) -> TreeNode:
        if root == None: return None
        if root.left:
            root.left = self.pruneTree(root.left)
        if root.right:
            root.right = self.pruneTree(root.right)

        if root.left is None and root.right is None and root.val == 0:
            return None
        return root