1325. Delete Leaves With a Given Value

[mah-shamim]

Discussed in #267

^{Originally posted by mah-shamim August 9, 2024}
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