Consider all the leaves of a binary tree, from left to right order, the values of those leaves form a leaf value sequence.
For example, in the given tree above, the leaf value sequence is (6, 7, 4, 9, 8)
.
Two binary trees are considered leaf-similar if their leaf value sequence is the same.
Return true
if and only if the two given trees with head nodes root1
and root2
are leaf-similar.
Example 1:
Input: root1 = [3,5,1,6,2,9,8,null,null,7,4], root2 = [3,5,1,6,7,4,2,null,null,null,null,null,null,9,8]
Output: true
Example 2:
Input: root1 = [1,2,3], root2 = [1,3,2]
Output: false
Constraints:
- The number of nodes in each tree will be in the range
[1, 200]
. - Both of the given trees will have values in the range
[0, 200]
.
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 leafSeq(self, root):
seq = []
nodes = [root]
while len(nodes) > 0:
curr = nodes.pop()
if curr:
if not curr.left and not curr.right:
seq.append(curr.val)
nodes.append(curr.left)
nodes.append(curr.right)
return seq
def leafSimilar(self, root1: Optional[TreeNode], root2: Optional[TreeNode]) -> bool:
return self.leafSeq(root1) == self.leafSeq(root2)
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