[Solved] Given a binary tree root and an integer target, delete all the leaf nodes with value target.

Table of Contents

Question

Given a binary tree `root` and an integer `target`, delete all the leaf nodes with value `target`.

Note that once you delete a leaf node with value `target`if its parent node becomes a leaf node and has the value `target`, it should also be deleted (you need to continue doing that until you cannot).

Example 1:

```Input: root = [1,2,3,2,null,2,4], target = 2
Output: [1,null,3,null,4]
Explanation: Leaf nodes in green with value (target = 2) are removed (Picture in left).
After removing, new nodes become leaf nodes with value (target = 2) (Picture in center).
```

Example 2:

```Input: root = [1,3,3,3,2], target = 3
Output: [1,3,null,null,2]
```

Example 3:

```Input: root = [1,2,null,2,null,2], target = 2
Output: [1]
Explanation: Leaf nodes in green with value (target = 2) are removed at each step.
```

Constraints:

• The number of nodes in the tree is in the range `[1, 3000]`.
• `1 <= Node.val, target <= 1000`

Python Solution

```# 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 removeLeafNodes(self, root: TreeNode, target: int) -> TreeNode:
if root:
root.left = self.removeLeafNodes(root.left,target)
root.right = self.removeLeafNodes(root.right,target)

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