https://leetcode.com/problems/delete-leaves-with-a-given-value/description/


class Solution {
public TreeNode removeLeafNodes(TreeNode root, int target) {
if(root == null) {
return null;
}
root.left = removeLeafNodes(root.left, target);
root.right = removeLeafNodes(root.right, target);
if(root.left == null && root.right == null && root.val == target) {
return null;
}
return root;
}
}