L872. Leaf-Similar Trees

找到两边的leaf，再比较

class Solution:
    def leafSimilar(self, root1, root2):
        """
        :type root1: TreeNode
        :type root2: TreeNode
        :rtype: bool
        """

        l1 = self.getleaf(root1,[])
        l2 = self.getleaf(root2,[])
        return l1 == l2

    def getleaf(self, root, leafs):
        if not root:
            return []
        if not root.left and not root.right:
            return [root.val]
        left = self.getleaf(root.left, leafs)
        right = self.getleaf(root.right, leafs)
        return left + right