Binary Tree Preorder Traversal, is a LeetCode problem from data-structures subdomain. In this post we will see how we can solve this challenge in Swift

Problem Description

You can find the full details of the problem Binary Tree Preorder Traversal at LeetCode

Solution

Time Complexity: O(n), Space Complexity: O(n)

Definition for a binary tree node.

public class TreeNode {

public var val: Int

public var left: TreeNode?

public var right: TreeNode?

public init(_ val: Int) {

    self.val = val

    self.left = nil

    self.right = nil

}

}

Please check the main.swift snippet for the solution.

This solution originally posted at: Github by @soapyigu