366.py

301-400/366.py

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+'''
+Given a binary tree, collect a tree's nodes as if you were doing this: Collect and remove all leaves, repeat until the tree is empty.
+
+ 
+
+Example:
+
+Input: [1,2,3,4,5]
+  
+          1
+         / \
+        2   3
+       / \     
+      4   5    
+
+Output: [[4,5,3],[2],[1]]
+ 
+
+Explanation:
+
+1. Removing the leaves [4,5,3] would result in this tree:
+
+          1
+         / 
+        2          
+ 
+
+2. Now removing the leaf [2] would result in this tree:
+
+          1          
+ 
+
+3. Now removing the leaf [1] would result in the empty tree:
+
+          []         
+[[3,5,4],[2],[1]], [[3,4,5],[2],[1]], etc, are also consider correct answers since per each level it doesn't matter the order on which elements are returned.
+'''
+# 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 findLeaves(self, root: TreeNode) -> List[List[int]]:
+
+
+        def getHeight(node):
+
+            if not node:
+                return -1
+            height = max(getHeight(node.left), getHeight(node.right)) + 1
+
+            if height == len(res):
+                res.append([])
+
+            res[height].append(node.val)
+            return height
+
+
+        res = []
+        getHeight(root)
+        return res