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| 1 | +""" |
| 2 | +Problem Link: https://leetcode.com/problems/find-leaves-of-binary-tree/ |
| 3 | + |
| 4 | +Given the root of a binary tree, collect a tree's nodes as if you were doing this: |
| 5 | +Collect all the leaf nodes. |
| 6 | +Remove all the leaf nodes. |
| 7 | +Repeat until the tree is empty. |
| 8 | + |
| 9 | +Example 1: |
| 10 | +Input: root = [1,2,3,4,5] |
| 11 | +Output: [[4,5,3],[2],[1]] |
| 12 | +Explanation: |
| 13 | +[[3,5,4],[2],[1]] and [[3,4,5],[2],[1]] are also considered correct answers since per |
| 14 | +each level it does not matter the order on which elements are returned. |
| 15 | + |
| 16 | +Example 2: |
| 17 | +Input: root = [1] |
| 18 | +Output: [[1]] |
| 19 | + |
| 20 | +Constraints: |
| 21 | +The number of nodes in the tree is in the range [1, 100]. |
| 22 | +-100 <= Node.val <= 100 |
| 23 | +""" |
| 24 | +# Definition for a binary tree node. |
| 25 | +# class TreeNode: |
| 26 | +# def __init__(self, val=0, left=None, right=None): |
| 27 | +# self.val = val |
| 28 | +# self.left = left |
| 29 | +# self.right = right |
| 30 | +class Solution: |
| 31 | + def findLeaves(self, root: Optional[TreeNode]) -> List[List[int]]: |
| 32 | + leaves = [] |
| 33 | + self.get_height(root, leaves) |
| 34 | + return leaves |
| 35 | + |
| 36 | + def get_height(self, root, leaves): |
| 37 | + if not root: |
| 38 | + return -1 |
| 39 | + |
| 40 | + height = 1 + max(self.get_height(root.left, leaves), |
| 41 | + self.get_height(root.right, leaves)) |
| 42 | + if height > len(leaves) - 1: |
| 43 | + leaves.append([]) |
| 44 | + |
| 45 | + leaves[height].append(root.val) |
| 46 | + |
| 47 | + return height |
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