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Abhishek Chaudhary

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# Leaf-Similar Trees

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)
``````