/** * Definition for a binary tree node. * class TreeNode(var `val`: Int = 0) { * var left: TreeNode? = null * var right: TreeNode? = null * } */ classSolution{ fun binaryTreePaths(root: TreeNode?): List<String> { val result = ArrayList<String>() binaryTreePaths2(root, "", result) return result } private fun binaryTreePaths2(root: TreeNode?, str: String, result: MutableList<String>){ var mStr = str if (root == null) return